diff --git a/source/libs/parser/src/parTranslater.c b/source/libs/parser/src/parTranslater.c
index a15d3675ae..26b96da4ce 100755
--- a/source/libs/parser/src/parTranslater.c
+++ b/source/libs/parser/src/parTranslater.c
@@ -7550,6 +7550,11 @@ static int32_t translateDeleteWhere(STranslateContext* pCxt, SDeleteStmt* pDelet
 }
 
 static int32_t translateDelete(STranslateContext* pCxt, SDeleteStmt* pDelete) {
+  const char* dbName = ((STableNode*)pDelete->pFromTable)->dbName;
+  if (IS_SYS_DBNAME(dbName)) {
+    return generateSyntaxErrMsgExt(&pCxt->msgBuf, TSDB_CODE_TSC_INVALID_OPERATION,
+                                   "Cannot delete from system database: `%s`", dbName);
+  }
   pCxt->pCurrStmt = (SNode*)pDelete;
   int32_t code = translateFrom(pCxt, &pDelete->pFromTable);
   if (TSDB_CODE_SUCCESS == code) {
@@ -8405,6 +8410,10 @@ static int32_t checkCreateDatabase(STranslateContext* pCxt, SCreateDatabaseStmt*
     return generateSyntaxErrMsgExt(&pCxt->msgBuf, TSDB_CODE_PAR_INVALID_IDENTIFIER_NAME,
                                    "The database name cannot contain '.'");
   }
+  if (IS_SYS_DBNAME(pStmt->dbName)) {
+    return generateSyntaxErrMsgExt(&pCxt->msgBuf, TSDB_CODE_TSC_INVALID_OPERATION,
+                                   "Cannot create system database: `%s`", pStmt->dbName);
+  }
   return checkDatabaseOptions(pCxt, pStmt->dbName, pStmt->pOptions);
 }
 
@@ -8594,9 +8603,13 @@ static int32_t translateCreateDatabase(STranslateContext* pCxt, SCreateDatabaseS
 }
 
 static int32_t translateDropDatabase(STranslateContext* pCxt, SDropDatabaseStmt* pStmt) {
+  if (IS_SYS_DBNAME(pStmt->dbName)) {
+    return generateSyntaxErrMsgExt(&pCxt->msgBuf, TSDB_CODE_TSC_INVALID_OPERATION, "Cannot drop system database: `%s`",
+                                   pStmt->dbName);
+  }
   SDropDbReq dropReq = {0};
   SName      name = {0};
-  int32_t    code = tNameSetDbName(&name, pCxt->pParseCxt->acctId, pStmt->dbName, strlen(pStmt->dbName));
+  int32_t code = tNameSetDbName(&name, pCxt->pParseCxt->acctId, pStmt->dbName, strlen(pStmt->dbName));
   if (TSDB_CODE_SUCCESS != code) return code;
   (void)tNameGetFullDbName(&name, dropReq.db);
   dropReq.ignoreNotExists = pStmt->ignoreNotExists;
@@ -8641,6 +8654,10 @@ static int32_t buildAlterDbReq(STranslateContext* pCxt, SAlterDatabaseStmt* pStm
 }
 
 static int32_t translateAlterDatabase(STranslateContext* pCxt, SAlterDatabaseStmt* pStmt) {
+  if (IS_SYS_DBNAME(pStmt->dbName)) {
+    return generateSyntaxErrMsgExt(&pCxt->msgBuf, TSDB_CODE_TSC_INVALID_OPERATION, "Cannot alter system database: `%s`",
+                                   pStmt->dbName);
+  }
   if (pStmt->pOptions->walLevel == 0) {
     TAOS_CHECK_RETURN(translateGetDbCfg(pCxt, pStmt->dbName, &pStmt->pOptions->pDbCfg));
     if (pStmt->pOptions->pDbCfg->replications > 1) {
@@ -9870,6 +9887,11 @@ static int32_t checkAlterSuperTableBySchema(STranslateContext* pCxt, SAlterTable
 }
 
 static int32_t checkAlterSuperTable(STranslateContext* pCxt, SAlterTableStmt* pStmt) {
+  if (IS_SYS_DBNAME(pStmt->dbName)) {
+    return generateSyntaxErrMsgExt(&pCxt->msgBuf, TSDB_CODE_TSC_INVALID_OPERATION,
+                                   "Cannot alter table of system database: `%s`.`%s`", pStmt->dbName, pStmt->tableName);
+  }
+
   if (TSDB_ALTER_TABLE_UPDATE_TAG_VAL == pStmt->alterType ||
       TSDB_ALTER_TABLE_UPDATE_MULTI_TAG_VAL == pStmt->alterType) {
     return generateSyntaxErrMsgExt(&pCxt->msgBuf, TSDB_CODE_PAR_INVALID_ALTER_TABLE,
@@ -15549,21 +15571,11 @@ int32_t serializeVgroupsDropTableBatch(SHashObj* pVgroupHashmap, SArray** pOut)
 static int32_t rewriteDropTableWithOpt(STranslateContext* pCxt, SQuery* pQuery) {
   int32_t         code = TSDB_CODE_SUCCESS;
   SDropTableStmt* pStmt = (SDropTableStmt*)pQuery->pRoot;
+  if (!pStmt->withOpt) return code;
+  pCxt->withOpt = true;
+
   SNode* pNode = NULL;
   char   pTableName[TSDB_TABLE_NAME_LEN] = {0};
-
-  FOREACH(pNode, pStmt->pTables) {
-    SDropTableClause* pClause = (SDropTableClause*)pNode;
-    if (IS_SYS_DBNAME(pClause->dbName)) {
-      return generateSyntaxErrMsgExt(&pCxt->msgBuf, TSDB_CODE_TSC_INVALID_OPERATION,
-                                     "Cannot drop table of system database: `%s`.`%s`", pClause->dbName,
-                                     pClause->tableName);
-    }
-  }
-
-  if (!pStmt->withOpt) return code;
-
-  pCxt->withOpt = true;
   FOREACH(pNode, pStmt->pTables) {
     SDropTableClause* pClause = (SDropTableClause*)pNode;
     for (int32_t i = 0; i < TSDB_TABLE_NAME_LEN; i++) {
@@ -15596,6 +15608,15 @@ static int32_t rewriteDropTable(STranslateContext* pCxt, SQuery* pQuery) {
   SNode*          pNode;
   SArray*         pTsmas = NULL;
 
+  FOREACH(pNode, pStmt->pTables) {
+    SDropTableClause* pClause = (SDropTableClause*)pNode;
+    if (IS_SYS_DBNAME(pClause->dbName)) {
+      return generateSyntaxErrMsgExt(&pCxt->msgBuf, TSDB_CODE_TSC_INVALID_OPERATION,
+                                     "Cannot drop table of system database: `%s`.`%s`", pClause->dbName,
+                                     pClause->tableName);
+    }
+  }
+
   TAOS_CHECK_RETURN(rewriteDropTableWithOpt(pCxt, pQuery));
 
   SHashObj* pVgroupHashmap = taosHashInit(4, taosGetDefaultHashFunction(TSDB_DATA_TYPE_INT), false, HASH_NO_LOCK);
@@ -15685,11 +15706,6 @@ static int32_t rewriteDropSuperTablewithOpt(STranslateContext* pCxt, SQuery* pQu
   if (!pStmt->withOpt) return code;
   pCxt->withOpt = true;
 
-  if (IS_SYS_DBNAME(pStmt->dbName)) {
-    return generateSyntaxErrMsgExt(&pCxt->msgBuf, TSDB_CODE_TSC_INVALID_OPERATION,
-                                   "Cannot drop table of system database: `%s`.`%s`", pStmt->dbName, pStmt->tableName);
-  }
-
   for (int32_t i = 0; i < TSDB_TABLE_NAME_LEN; i++) {
     if (pStmt->tableName[i] == '\0') {
       break;
@@ -15719,6 +15735,11 @@ static int32_t rewriteDropSuperTablewithOpt(STranslateContext* pCxt, SQuery* pQu
 }
 
 static int32_t rewriteDropSuperTable(STranslateContext* pCxt, SQuery* pQuery) {
+  SDropSuperTableStmt* pStmt = (SDropSuperTableStmt*)pQuery->pRoot;
+  if (IS_SYS_DBNAME(pStmt->dbName)) {
+    return generateSyntaxErrMsgExt(&pCxt->msgBuf, TSDB_CODE_TSC_INVALID_OPERATION,
+                                   "Cannot drop table of system database: `%s`.`%s`", pStmt->dbName, pStmt->tableName);
+  }
   TAOS_CHECK_RETURN(rewriteDropSuperTablewithOpt(pCxt, pQuery));
   TAOS_RETURN(0);
 }
@@ -16272,6 +16293,11 @@ static int32_t rewriteAlterTableImpl(STranslateContext* pCxt, SAlterTableStmt* p
 static int32_t rewriteAlterTable(STranslateContext* pCxt, SQuery* pQuery) {
   SAlterTableStmt* pStmt = (SAlterTableStmt*)pQuery->pRoot;
 
+  if (IS_SYS_DBNAME(pStmt->dbName)) {
+    return generateSyntaxErrMsgExt(&pCxt->msgBuf, TSDB_CODE_TSC_INVALID_OPERATION,
+                                   "Cannot alter table of system database: `%s`.`%s`", pStmt->dbName, pStmt->tableName);
+  }
+
   if (pStmt->dataType.type == TSDB_DATA_TYPE_JSON && pStmt->alterType == TSDB_ALTER_TABLE_ADD_COLUMN) {
     return generateSyntaxErrMsg(&pCxt->msgBuf, TSDB_CODE_PAR_INVALID_COL_JSON);
   }
diff --git a/tests/parallel_test/cases.task b/tests/parallel_test/cases.task
index c4ebb8d78b..825e5037ab 100644
--- a/tests/parallel_test/cases.task
+++ b/tests/parallel_test/cases.task
@@ -733,7 +733,6 @@
 ,,y,system-test,./pytest.sh python3 ./test.py -f 1-insert/tb_100w_data_order.py
 ,,y,system-test,./pytest.sh python3 ./test.py -f 1-insert/delete_childtable.py
 ,,y,system-test,./pytest.sh python3 ./test.py -f 1-insert/delete_normaltable.py
-,,y,system-test,./pytest.sh python3 ./test.py -f 1-insert/delete_systable.py
 ,,y,system-test,./pytest.sh python3 ./test.py -f 1-insert/keep_expired.py
 ,,y,system-test,./pytest.sh python3 ./test.py -f 1-insert/stmt_error.py
 ,,y,system-test,./pytest.sh python3 ./test.py -f 1-insert/drop.py
diff --git a/tests/system-test/1-insert/ddl_in_sysdb.py b/tests/system-test/1-insert/ddl_in_sysdb.py
index d2707c0702..4065f593f5 100644
--- a/tests/system-test/1-insert/ddl_in_sysdb.py
+++ b/tests/system-test/1-insert/ddl_in_sysdb.py
@@ -1,43 +1,87 @@
-import taos
-import sys
-import datetime
-import inspect
-import random
-from util.dnodes import TDDnode
-from util.dnodes import tdDnodes
 
+###################################################################
+#           Copyright (c) 2016 by TAOS Technologies, Inc.
+#                     All rights reserved.
+#
+#  This file is proprietary and confidential to TAOS Technologies.
+#  No part of this file may be reproduced, stored, transmitted,
+#  disclosed or used in any form or by any means other than as
+#  expressly provided by the written permission from Jianhui Tao
+#
+###################################################################
+
+# -*- coding: utf-8 -*-
+
+import random
+import string
+
+from numpy import logspace
+from util import constant
 from util.log import *
-from util.sql import *
 from util.cases import *
+from util.sql import *
+from util.common import *
+from util.sqlset import TDSetSql
+
+sysdb_tables = { 
+    "information_schema": ["ins_dnodes", "ins_mnodes", "ins_modules", "ins_qnodes", "ins_snodes", "ins_cluster", "ins_databases", "ins_functions", "ins_indexes", "ins_stables", "ins_tables", "ins_tags", "ins_columns", "ins_users", "ins_grants", "ins_vgroups", "ins_configs", "ins_dnode_variables", "ins_topics", "ins_subscriptions", "ins_streams", "ins_streams_tasks", "ins_vnodes", "ins_user_privileges", "undefined"], 
+    "performance_schema": ["perf_connections", "perf_queries", "perf_consumers", "perf_trans", "perf_apps", "undefined"]
+    }
 
 class TDTestCase:
     def init(self, conn, logSql, replicaVar=1):
         self.replicaVar = int(replicaVar)
-        tdLog.debug(f"start to excute {__file__}")
-        tdSql.init(conn.cursor(), True)
+        tdLog.debug("start to execute %s" % __file__)
+        tdSql.init(conn.cursor())
 
-        self.testcasePath = os.path.split(__file__)[0]
-        self.testcasePath = self.testcasePath.replace('\\', '//')
-        self.sysdb = "information_schema"
+    def ddl_sysdb(self):
+        for db, _ in sysdb_tables.items():
+            tdSql.error(f'create database {db}', expectErrInfo="Cannot create system database", fullMatched=False)
+            tdSql.error(f'create database {db} vgroups 10', expectErrInfo="Cannot create system database", fullMatched=False)
+            tdSql.error(f'alter database {db} wal_level 0', expectErrInfo="Cannot alter system database", fullMatched=False)
+            tdSql.error(f'alter database {db} cachemodel \'none\'', expectErrInfo="Cannot alter system database", fullMatched=False)
+            tdSql.error(f'drop database {db}', expectErrInfo="Cannot drop system database", fullMatched=False)
+            tdSql.error(f'drop database {db}', expectErrInfo="Cannot drop system database", fullMatched=False)    
 
-    def test_ddl(self):
-        tdSql.execute(f"use {self.sysdb}")
-        tdSql.error(f'create stable ins_test (ts timestamp, a int) tags (b int);', expectErrInfo="Cannot create table of system database", fullMatched=False)
-        tdSql.error(f'create table ins_test (ts timestamp, a int);', expectErrInfo="Cannot create table of system database", fullMatched=False)
-        tdSql.error(f'drop table ins_users;', expectErrInfo="Cannot drop table of system database", fullMatched=False)
+    def ddl_systb(self):
+        for db, tbs in sysdb_tables.items():
+            tdSql.execute(f'use {db}')
+            for tb in tbs:
+                tdSql.error(f'create table {tb} (ts timestamp, c0 int)', expectErrInfo="Cannot create table of system database", fullMatched=False)
+                tdSql.error(f'create table {db}.{tb} (ts timestamp, c0 int)', expectErrInfo="Cannot create table of system database", fullMatched=False)
+                tdSql.error(f'create stable {tb} (ts timestamp, c0 int) tags(t0 int)', expectErrInfo="Cannot create table of system database", fullMatched=False)
+                tdSql.error(f'create stable {db}.{tb} (ts timestamp, c0 int) tags(t0 int)', expectErrInfo="Cannot create table of system database", fullMatched=False)
+                tdSql.error(f'alter table {tb} add column c1 int', expectErrInfo="Cannot alter table of system database", fullMatched=False)
+                tdSql.error(f'alter table {db}.{tb} add column c1 int', expectErrInfo="Cannot alter table of system database", fullMatched=False)
+                tdSql.error(f'alter stable {tb} add column c1 int', expectErrInfo="Cannot alter table of system database", fullMatched=False)
+                tdSql.error(f'alter stable {db}.{tb} add column c1 int', expectErrInfo="Cannot alter table of system database", fullMatched=False)
+                tdSql.error(f'insert into {tb} values (now,1)', expectErrInfo="System table not allowed", fullMatched=False)
+                tdSql.error(f'insert into {db}.{tb} values (now,1)', expectErrInfo="System table not allowed", fullMatched=False)
+                tdSql.error(f'delete from {tb}', expectErrInfo="Cannot delete from system database", fullMatched=False)
+                tdSql.error(f'delete from {db}.{tb}', expectErrInfo="Cannot delete from system database", fullMatched=False)
+                tdSql.error(f'delete from {tb} where ts >= 0', expectErrInfo="Cannot delete from system database", fullMatched=False)
+                tdSql.error(f'delete from {db}.{tb} where ts >= 0', expectErrInfo="Cannot delete from system database", fullMatched=False)
+                tdSql.error(f'drop table {tb}', expectErrInfo="Cannot drop table of system database", fullMatched=False)
+                tdSql.error(f'drop table {db}.{tb}', expectErrInfo="Cannot drop table of system database", fullMatched=False)
+                tdSql.error(f'drop stable {tb}', expectErrInfo="Cannot drop table of system database", fullMatched=False)
+                tdSql.error(f'drop stable {db}.{tb}', expectErrInfo="Cannot drop table of system database", fullMatched=False)
+                tdSql.error(f'drop table with {tb}', expectErrInfo="Cannot drop table of system database", fullMatched=False)
+                tdSql.error(f'drop table with {db}.{tb}', expectErrInfo="Cannot drop table of system database", fullMatched=False)
+                tdSql.error(f'drop stable with {tb}', expectErrInfo="Cannot drop table of system database", fullMatched=False)
+                tdSql.error(f'drop stable with {db}.{tb}', expectErrInfo="Cannot drop table of system database", fullMatched=False)
+
+    def ddl_in_sysdb(self):
+        self.ddl_sysdb()
+        self.ddl_systb()
 
     def run(self):
-        tdSql.prepare()
-        
-        startTime_all = time.time()
-        self.test_ddl()
-        endTime_all = time.time()
-        print("total time %ds" % (endTime_all - startTime_all))
-
+        self.ddl_in_sysdb()
+        tdDnodes.stoptaosd(1)
+        tdDnodes.starttaosd(1)
+        self.ddl_in_sysdb()
     def stop(self):
         tdSql.close()
         tdLog.success("%s successfully executed" % __file__)
-        
 
 tdCases.addWindows(__file__, TDTestCase())
 tdCases.addLinux(__file__, TDTestCase())
diff --git a/tests/system-test/1-insert/delete_systable.py b/tests/system-test/1-insert/delete_systable.py
deleted file mode 100644
index 40422a7515..0000000000
--- a/tests/system-test/1-insert/delete_systable.py
+++ /dev/null
@@ -1,111 +0,0 @@
-
-###################################################################
-#           Copyright (c) 2016 by TAOS Technologies, Inc.
-#                     All rights reserved.
-#
-#  This file is proprietary and confidential to TAOS Technologies.
-#  No part of this file may be reproduced, stored, transmitted,
-#  disclosed or used in any form or by any means other than as
-#  expressly provided by the written permission from Jianhui Tao
-#
-###################################################################
-
-# -*- coding: utf-8 -*-
-
-import random
-import string
-
-from numpy import logspace
-from util import constant
-from util.log import *
-from util.cases import *
-from util.sql import *
-from util.common import *
-from util.sqlset import TDSetSql
-
-info_schema_db = "information_schema"
-perf_schema_db = "performance_schema"
-
-info_schema_tables = [
-    "ins_dnodes",
-    "ins_mnodes",
-    "ins_modules",
-    "ins_qnodes",
-    "ins_snodes",
-    "ins_cluster",
-    "ins_databases",
-    "ins_functions",
-    "ins_indexes",
-    "ins_stables",
-    "ins_tables",
-    "ins_tags",
-    "ins_columns",
-    "ins_users",
-    "ins_grants",
-    "ins_vgroups",
-    "ins_configs",
-    "ins_dnode_variables",
-    "ins_topics",
-    "ins_subscriptions",
-    "ins_streams",
-    "ins_streams_tasks",
-    "ins_vnodes",
-    "ins_user_privileges"
-]
-
-perf_schema_tables = [
-    "perf_connections",
-    "perf_queries",
-    "perf_consumers",
-    "perf_trans",
-    "perf_apps"
-]
-
-class TDTestCase:
-    def init(self, conn, logSql, replicaVar=1):
-        self.replicaVar = int(replicaVar)
-        tdLog.debug("start to execute %s" % __file__)
-        tdSql.init(conn.cursor())
-
-    def delete_systb(self):
-        tdSql.execute(f'use {info_schema_db}')
-        for i in info_schema_tables:
-            tdSql.error(f'delete from {i}')
-            tdSql.error(f'delete from {info_schema_db}.{i}')
-            tdSql.error(f'delete from {i} where ts >= 0')
-            tdSql.error(f'delete from {info_schema_db}.{i} where ts >= 0')
-
-        tdSql.execute(f'use {perf_schema_db}')
-        for i in perf_schema_tables:
-            tdSql.error(f'delete from {i}')
-            tdSql.error(f'delete from {perf_schema_db}.{i}')
-            tdSql.error(f'delete from {i} where ts >= 0')
-            tdSql.error(f'delete from {perf_schema_db}.{i} where ts >= 0')
-
-    def drop_systb(self):
-        tdSql.execute(f'use {info_schema_db}')
-        for i in info_schema_tables:
-            tdSql.error(f'drop table {i}')
-            tdSql.error(f'drop {info_schema_db}.{i}')
-        tdSql.error(f'drop database {info_schema_db}')
-
-        tdSql.execute(f'use {perf_schema_db}')
-        for i in perf_schema_tables:
-            tdSql.error(f'drop table {i}')
-            tdSql.error(f'drop table {perf_schema_db}.{i}')
-        tdSql.error(f'drop database {perf_schema_db}')
-
-    def delete_from_systb(self):
-        self.delete_systb()
-        self.drop_systb()
-    def run(self):
-        self.delete_from_systb()
-        tdDnodes.stoptaosd(1)
-        tdDnodes.starttaosd(1)
-        self.delete_from_systb()
-    def stop(self):
-        tdSql.close()
-        tdLog.success("%s successfully executed" % __file__)
-
-tdCases.addWindows(__file__, TDTestCase())
-tdCases.addLinux(__file__, TDTestCase())
diff --git a/tests/system-test/win-test-file b/tests/system-test/win-test-file
index 1127499ec8..b3e7e5b4d3 100644
--- a/tests/system-test/win-test-file
+++ b/tests/system-test/win-test-file
@@ -562,7 +562,7 @@ python3 ./test.py -f 1-insert/update_data.py
 python3 ./test.py -f 1-insert/tb_100w_data_order.py
 python3 ./test.py -f 1-insert/delete_childtable.py
 python3 ./test.py -f 1-insert/delete_normaltable.py
-python3 ./test.py -f 1-insert/delete_systable.py
+python3 ./test.py -f 1-insert/ddl_in_sysdb.py
 python3 ./test.py -f 1-insert/keep_expired.py
 python3 ./test.py -f 1-insert/stmt_error.py
 python3 ./test.py -f 1-insert/drop.py