diff --git a/source/common/src/tdataformat.c b/source/common/src/tdataformat.c
index f97f9c0c11..02dfbfebfe 100644
--- a/source/common/src/tdataformat.c
+++ b/source/common/src/tdataformat.c
@@ -1248,6 +1248,7 @@ static int32_t tPutTagVal(uint8_t *p, STagVal *pTagVal, int8_t isJson) {
     n += tPutCStr(p ? p + n : p, pTagVal->pKey);
   } else {
     n += tPutI16v(p ? p + n : p, pTagVal->cid);
+    ASSERTS(pTagVal->cid > 0, "Invalid tag cid:%" PRIi16, pTagVal->cid);
   }
 
   // type
diff --git a/source/libs/parser/src/parInsertSql.c b/source/libs/parser/src/parInsertSql.c
index 9347f94e8d..a3b6f01e3a 100644
--- a/source/libs/parser/src/parInsertSql.c
+++ b/source/libs/parser/src/parInsertSql.c
@@ -700,7 +700,8 @@ static int32_t parseBoundTagsClause(SInsertParseContext* pCxt, SVnodeModifyOpStm
 
 static int32_t parseTagValue(SInsertParseContext* pCxt, SVnodeModifyOpStmt* pStmt, const char** ppSql, SSchema* pTagSchema, SToken* pToken,
                              SArray* pTagName, SArray* pTagVals, STag** pTag) {
-  if (!isNullValue(pTagSchema->type, pToken)) {
+  bool isNull = isNullValue(pTagSchema->type, pToken);
+  if (!isNull) {
     taosArrayPush(pTagName, pTagSchema->name);
   }
 
@@ -709,13 +710,15 @@ static int32_t parseTagValue(SInsertParseContext* pCxt, SVnodeModifyOpStmt* pStm
       return buildSyntaxErrMsg(&pCxt->msg, "json string too long than 4095", pToken->z);
     }
 
-    if (isNullValue(pTagSchema->type, pToken)) {
+    if (isNull) {
       return tTagNew(pTagVals, 1, true, pTag);
     } else {
       return parseJsontoTagData(pToken->z, pTagVals, pTag, &pCxt->msg);
     }
   }
 
+  if (isNull) return 0;
+
   STagVal val = {0};
   int32_t code =
       parseTagToken(ppSql, pToken, pTagSchema, pStmt->pTableMeta->tableInfo.precision, &val, &pCxt->msg);
diff --git a/tests/script/tsim/insert/insert_stb.sim b/tests/script/tsim/insert/insert_stb.sim
index 4c0797e2a7..14ff2261c2 100644
--- a/tests/script/tsim/insert/insert_stb.sim
+++ b/tests/script/tsim/insert/insert_stb.sim
@@ -66,6 +66,29 @@ if $rows != 1 then
   return -1
 endi
 
+sql insert into st(tbname, ts, f, t) values('ct2',now,20,NULL)('ct3',now,30,NULL)
+sql insert into st(tbname, t, ts, f) values('ct4',NULL, now,20)('ct5',NULL, now,30)
+sql show create table ct2
+sql show create table ct3
+sql show create table ct4
+sql show create table ct5
+sql show tags from ct2
+if $data05 != NULL then
+  return -1
+endi
+sql show tags from ct3
+if $data05 != NULL then
+  return -1
+endi
+sql show tags from ct4
+if $data05 != NULL then
+  return -1
+endi
+sql show tags from ct5
+if $data05 != NULL then
+  return -1
+endi
+
 sql_error insert into d2.st values(now, 1, 1)
 sql_error insert into d2.st(ts, f) values(now, 1);
 sql_error insert into d2.st(ts, f, tbname) values(now, 1);
diff --git a/tests/script/tsim/parser/columnValue_bigint.sim b/tests/script/tsim/parser/columnValue_bigint.sim
index 0a024029a5..056855eea2 100644
--- a/tests/script/tsim/parser/columnValue_bigint.sim
+++ b/tests/script/tsim/parser/columnValue_bigint.sim
@@ -17,6 +17,7 @@ sql create table mt_bigint (ts timestamp, c bigint) tags (tagname bigint)
 
 ## case 00: static create table for test tag values
 sql create table st_bigint_0  using mt_bigint tags (NULL)
+sql show create table st_bigint_0
 sql show tags from  st_bigint_0
 if $data05 != NULL then
   return -1
@@ -173,6 +174,7 @@ endi
 
 ## case 02: dynamic create table for test tag values
 sql insert into st_bigint_16 using mt_bigint tags (NULL)   values (now, NULL)
+sql show create table st_bigint_16
 sql show tags from  st_bigint_16
 if $data05 != NULL then
   return -1
diff --git a/tests/script/tsim/parser/columnValue_bool.sim b/tests/script/tsim/parser/columnValue_bool.sim
index ad4232d884..2553e6805a 100644
--- a/tests/script/tsim/parser/columnValue_bool.sim
+++ b/tests/script/tsim/parser/columnValue_bool.sim
@@ -17,6 +17,7 @@ sql create table mt_bool (ts timestamp, c bool) tags (tagname bool)
 
 ## case 00: static create table for test tag values
 sql create table st_bool_0  using mt_bool tags (NULL)
+sql show create table st_bool_0
 sql show tags from st_bool_0
 if $data05 != NULL then
   print ==1== expect: NULL, actually: $data05
@@ -291,6 +292,7 @@ endi
 
 ## case 02: dynamic create table for test tag values
 sql insert into st_bool_16 using mt_bool tags (NULL)   values (now, NULL)
+sql show create table st_bool_16
 sql show tags from st_bool_16
 if $data05 != NULL then
   print ==33== expect: NULL, actually: $data00
diff --git a/tests/script/tsim/parser/columnValue_float.sim b/tests/script/tsim/parser/columnValue_float.sim
index b2db7dff2b..4dcda33224 100644
--- a/tests/script/tsim/parser/columnValue_float.sim
+++ b/tests/script/tsim/parser/columnValue_float.sim
@@ -17,6 +17,7 @@ sql create table mt_float (ts timestamp, c float) tags (tagname float)
 
 ## case 00: static create table for test tag values
 sql create table st_float_0  using mt_float tags (NULL)
+sql show create table st_float_0
 sql show tags from  st_float_0
 if $data05 != NULL then
   return -1
@@ -299,6 +300,7 @@ endi
 
 ## case 02: dynamic create table for test tag values
 sql insert into st_float_16 using mt_float tags (NULL)   values (now, NULL)
+sql show create table st_float_16
 sql show tags from  st_float_16
 if $data05 != NULL then
   return -1
diff --git a/tests/script/tsim/parser/columnValue_int.sim b/tests/script/tsim/parser/columnValue_int.sim
index 4a3b8ebd0b..e68ae6f13f 100644
--- a/tests/script/tsim/parser/columnValue_int.sim
+++ b/tests/script/tsim/parser/columnValue_int.sim
@@ -17,6 +17,7 @@ sql create table mt_int (ts timestamp, c int) tags (tagname int)
 
 ## case 00: static create table for test tag values
 sql create table st_int_0  using mt_int tags (NULL)
+sql show create table st_int_0
 sql show tags from  st_int_0
 if $data05 != NULL then
   return -1
@@ -172,6 +173,7 @@ endi
 
 ## case 02: dynamic create table for test tag values
 sql insert into st_int_16 using mt_int tags (NULL)   values (now, NULL)
+sql show create table st_int_16
 sql show tags from  st_int_16
 if $data05 != NULL then
   return -1
diff --git a/tests/script/tsim/parser/columnValue_smallint.sim b/tests/script/tsim/parser/columnValue_smallint.sim
index eb364f3630..f9be6ebd52 100644
--- a/tests/script/tsim/parser/columnValue_smallint.sim
+++ b/tests/script/tsim/parser/columnValue_smallint.sim
@@ -20,6 +20,7 @@ sql create table mt_smallint (ts timestamp, c smallint) tags (tagname smallint)
 
 ## case 00: static create table for test tag values
 sql create table st_smallint_0  using mt_smallint tags (NULL)
+sql show create table st_smallint_0
 sql show tags from st_smallint_0
 if $data05 != NULL then
   return -1
@@ -175,6 +176,7 @@ endi
 
 ## case 02: dynamic create table for test tag values
 sql insert into st_smallint_16 using mt_smallint tags (NULL)   values (now, NULL)
+sql show create table st_smallint_16
 sql show tags from st_smallint_16
 if $data05 != NULL then
   return -1
diff --git a/tests/script/tsim/parser/columnValue_tinyint.sim b/tests/script/tsim/parser/columnValue_tinyint.sim
index d7938aa739..7d0f10a30d 100644
--- a/tests/script/tsim/parser/columnValue_tinyint.sim
+++ b/tests/script/tsim/parser/columnValue_tinyint.sim
@@ -17,6 +17,7 @@ sql create table mt_tinyint (ts timestamp, c tinyint) tags (tagname tinyint)
 
 ## case 00: static create table for test tag values
 sql create table st_tinyint_0  using mt_tinyint tags (NULL)
+sql show create table st_tinyint_0
 sql show tags from  st_tinyint_0
 if $data05 != NULL then
   print expect NULL, actually: $data05
@@ -173,6 +174,7 @@ endi
 
 ## case 02: dynamic create table for test tag values
 sql insert into st_tinyint_16 using mt_tinyint tags (NULL)   values (now, NULL)
+sql show create table st_tinyint_16
 sql show tags from  st_tinyint_16
 if $data05 != NULL then
   return -1
diff --git a/tests/script/tsim/parser/null_char.sim b/tests/script/tsim/parser/null_char.sim
index 098f4061c1..9d476b5227 100644
--- a/tests/script/tsim/parser/null_char.sim
+++ b/tests/script/tsim/parser/null_char.sim
@@ -13,6 +13,7 @@ sql use $db
 #### case 0: field NULL, or 'NULL'
 sql create table mt1 (ts timestamp, col1 int, col2 bigint, col3 float, col4 double, col5 binary(8), col6 bool, col7 smallint, col8 tinyint, col9 nchar(8)) tags (tag1 binary(8), tag2 nchar(8), tag3 int, tag4 bigint, tag5 bool, tag6 float)
 sql create table st1 using mt1 tags (NULL, 'NULL', 100, 1000, 'false', 9.123)
+sql show create table st1
 sql insert into st1 values ('2019-01-01 09:00:00.000', 123, -123, 3.0, 4.0, 'binary', true, 1000, 121, 'nchar')
 sql insert into st1 values ('2019-01-01 09:00:01.000', '456', '456', '3.33', '4.444', 'binary', 'true', '1001', '122', 'nchar')
 sql insert into st1 values ('2019-01-01 09:00:02.000', NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL)
@@ -117,6 +118,7 @@ if $rows != 0 then
 endi
 
 sql create table st3 using mt2 tags (NULL, 'ABC', 103, 'FALSE')
+sql show create table st3
 sql insert into st3 (ts, col1) values(now, 1)
 sql select tag1, tag2, tag3, tag5 from st3
 if $rows != 1 then
diff --git a/tests/system-test/2-query/json_tag.py b/tests/system-test/2-query/json_tag.py
index ebd580efd4..8db92f38a2 100644
--- a/tests/system-test/2-query/json_tag.py
+++ b/tests/system-test/2-query/json_tag.py
@@ -394,9 +394,12 @@ class TDTestCase:
         tdSql.execute(f"create table if not exists {dbname}.jsons3(ts timestamp, dataInt int, dataBool bool, dataStr nchar(50), dataStrBin binary(150)) tags(jtag json)")
         tdSql.execute(f"insert into {dbname}.jsons3_1 using {dbname}.jsons3 tags('{{\"tag1\":\"fff\",\"tag2\":5, \"tag3\":true}}') values(1591060618000, 3, false, 'json3', '你是3')")
         tdSql.execute(f"insert into {dbname}.jsons3_2 using {dbname}.jsons3 tags('{{\"tag1\":5,\"tag2\":\"beijing\"}}') values (1591060638000, 2, true, 'json3', 'sss')")
+        tdSql.execute(f"insert into {dbname}.jsons3_3 using {dbname}.jsons3 tags(NULL) values (1591060638000, 2, true, 'json3', 'sss')")
         tdSql.query(f"select 'sss',33,a.jtag->'tag3' from {dbname}.jsons2 a,jsons3 b where a.ts=b.ts and a.jtag->'tag1'=b.jtag->'tag1'")
         tdSql.checkData(0, 0, "sss")
         tdSql.checkData(0, 2, "true")
+        tdSql.query(f"show create table jsons3_3")
+        tdSql.checkNotEqual(tdSql.queryResult[0][1].find("TAGS (null)"), 0)
 
         res = tdSql.getColNameList(f"select 'sss',33,a.jtag->'tag3' from {dbname}.jsons2 a,jsons3 b where a.ts=b.ts and a.jtag->'tag1'=b.jtag->'tag1'")
         cname_list = []