diff --git a/src/connector/jdbc/src/main/java/com/taosdata/jdbc/TSDBStatement.java b/src/connector/jdbc/src/main/java/com/taosdata/jdbc/TSDBStatement.java
index c3756aff34..c856c03a83 100644
--- a/src/connector/jdbc/src/main/java/com/taosdata/jdbc/TSDBStatement.java
+++ b/src/connector/jdbc/src/main/java/com/taosdata/jdbc/TSDBStatement.java
@@ -51,13 +51,17 @@ public class TSDBStatement implements Statement {
         if (isClosed) {
             throw new SQLException("Invalid method call on a closed statement.");
         }
-		this.connecter.executeQuery(sql);
+		System.out.println(sql);
+		long res = this.connecter.executeQuery(sql);
 
 		long resultSetPointer = this.connecter.getResultSet();
 
 		if (resultSetPointer == TSDBConstants.JNI_CONNECTION_NULL) {
+			this.connecter.freeResultSet(res);
 			throw new SQLException(TSDBConstants.FixErrMsg(TSDBConstants.JNI_CONNECTION_NULL));
 		} else if (resultSetPointer == TSDBConstants.JNI_NULL_POINTER) {
+//			create/insert/update/del/alter
+			this.connecter.freeResultSet(res);
 			return null;
 		} else {
 			return new TSDBResultSet(this.connecter, resultSetPointer);
diff --git a/src/connector/jdbc/src/test/java/com/taosdata/jdbc/TSDBAsyncSubscribeTest.java b/src/connector/jdbc/src/test/java/com/taosdata/jdbc/TSDBAsyncSubscribeTest.java
index 530b47d277..245ababae1 100644
--- a/src/connector/jdbc/src/test/java/com/taosdata/jdbc/TSDBAsyncSubscribeTest.java
+++ b/src/connector/jdbc/src/test/java/com/taosdata/jdbc/TSDBAsyncSubscribeTest.java
@@ -21,7 +21,7 @@ public class TSDBAsyncSubscribeTest {
     String topic = "test";
     long subscribId = 0;
 
-//    @Before
+    @Before
     public void createDatabase() throws SQLException {
         try {
             Class.forName("com.taosdata.jdbc.TSDBDriver");
@@ -43,7 +43,7 @@ public class TSDBAsyncSubscribeTest {
         }
     }
 
-//    @Test
+    @Test
     public void subscribe() throws Exception {
         TSDBSubscribe subscribe = null;
         try {
@@ -70,7 +70,6 @@ public class TSDBAsyncSubscribeTest {
 
         @Override
         public void invoke(TSDBResultSet resultSet) {
-             System.out.println("resultSet");
             try {
                 while (null != resultSet && resultSet.next()) {
                     System.out.print("callback_" + name + ": ");
@@ -87,7 +86,7 @@ public class TSDBAsyncSubscribeTest {
         }
     }
 
-//    @After
+    @After
     public void close() throws Exception {
         statement.executeQuery("drop database test");
         statement.close();
diff --git a/src/connector/jdbc/src/test/java/com/taosdata/jdbc/TSDBImportTest.java b/src/connector/jdbc/src/test/java/com/taosdata/jdbc/TSDBImportTest.java
index 1fd15b2dfd..8b3c9f3141 100644
--- a/src/connector/jdbc/src/test/java/com/taosdata/jdbc/TSDBImportTest.java
+++ b/src/connector/jdbc/src/test/java/com/taosdata/jdbc/TSDBImportTest.java
@@ -4,10 +4,7 @@ import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
 
-import java.sql.Connection;
-import java.sql.DriverManager;
-import java.sql.SQLException;
-import java.sql.Statement;
+import java.sql.*;
 import java.util.Properties;
 
 import static org.junit.Assert.assertEquals;
@@ -40,20 +37,33 @@ public class TSDBImportTest {
 
     @Test
     public void insertInto() throws Exception {
-        long ts = System.currentTimeMillis();
+        long ts = 1496732686000l;
 
         for (int i = 0; i < 50; i++) {
-            ts += i;
+            ts ++;
             int row = statement.executeUpdate("insert into " + dbName + "." + tName + " values (" + ts + ", " + (100 + i) + ", " + i + ")");
-            System.out.println("insert into " + dbName + "." + tName + " values (" + ts + ", " + (100 + i) + ", " + i + ")" + "\t" + row);
+            System.out.println("insert into " + dbName + "." + tName + " values (" + ts + ", " + (100 + i) + ", " + i + ")\t" + row);
             assertEquals(1, row);
         }
     }
 
+    @Test
+    public void selectData() throws Exception {
+        String sql = "select * from test.t0";
+        ResultSet resSet = statement.executeQuery(sql);
+
+        while (resSet.next()) {
+            for (int i = 1; i <= resSet.getMetaData().getColumnCount(); i++) {
+                System.out.printf(i + ": " + resSet.getString(i) + "\t");
+            }
+        }
+        resSet.close();
+    }
+
     @Test
     public void importInto() throws Exception {
         // 避免时间重复
-        long ts = System.currentTimeMillis() + 1000;
+        long ts = 1496732686000l;
 
         StringBuilder sqlBuilder = new StringBuilder("insert into ").append(dbName).append(".").append(tName).append(" values ");
 
@@ -68,9 +78,9 @@ public class TSDBImportTest {
         assertEquals(10, rows);
     }
 
-    @After
+//    @After
     public void close() throws Exception {
-        statement.executeQuery("drop database " + dbName);
+        statement.executeUpdate("drop database " + dbName);
         statement.close();
         connection.close();
     }
diff --git a/src/connector/jdbc/src/test/java/com/taosdata/jdbc/TSDBSubscribeTest.java b/src/connector/jdbc/src/test/java/com/taosdata/jdbc/TSDBSubscribeTest.java
index b7c6313587..11698ea299 100644
--- a/src/connector/jdbc/src/test/java/com/taosdata/jdbc/TSDBSubscribeTest.java
+++ b/src/connector/jdbc/src/test/java/com/taosdata/jdbc/TSDBSubscribeTest.java
@@ -20,7 +20,7 @@ public class TSDBSubscribeTest {
     String host = "localhost";
     String topic = "test";
 
-//    @Before
+    @Before
     public void createDatabase() throws SQLException {
         try {
             Class.forName("com.taosdata.jdbc.TSDBDriver");
@@ -42,7 +42,7 @@ public class TSDBSubscribeTest {
         }
     }
 
-//    @Test
+    @Test
     public void subscribe() throws Exception {
         TSDBSubscribe subscribe = null;
         long subscribId = 0;
@@ -81,7 +81,7 @@ public class TSDBSubscribeTest {
         }
     }
 
-//    @After
+    @After
     public void close() throws Exception {
         statement.executeQuery("drop database " + dbName);
         statement.close();