diff --git a/tests/examples/c/schemaless.c b/tests/examples/c/schemaless.c
index 830e59880198b0ef2c21cd78448fd6cb80f98b2f..6d1b257d4c495e72103dad9613f6e1bc3738bfd8 100644
--- a/tests/examples/c/schemaless.c
+++ b/tests/examples/c/schemaless.c
@@ -8,8 +8,9 @@
 #include <time.h>
 #include <unistd.h>
 
+int numThreads = 8;
 int numSuperTables = 8;
-int numChildTables = 4;
+int numChildTablesPerThread = 4;
 int numRowsPerChildTable = 2048;
 
 void shuffle(char** lines, size_t n) {
@@ -24,12 +25,37 @@ void shuffle(char** lines, size_t n) {
   }
 }
 
+void printThreadId(pthread_t id, char* buf)
+{
+  size_t i;
+  for (i = sizeof(i); i; --i)
+    sprintf(buf + strlen(buf), "%02x", *(((unsigned char*) &id) + i - 1));
+}
+
 static int64_t getTimeInUs() {
   struct timeval systemTime;
   gettimeofday(&systemTime, NULL);
   return (int64_t)systemTime.tv_sec * 1000000L + (int64_t)systemTime.tv_usec;
 }
 
+typedef struct  {
+  TAOS* taos;
+  char** lines;
+  int numLines;
+} SThreadInsertArgs;
+
+static void* insertLines(void* args) {
+  SThreadInsertArgs* insertArgs = (SThreadInsertArgs*) args;
+  char tidBuf[32] = {0};
+  printThreadId(pthread_self(), tidBuf);
+  printf("%s, thread: 0x%s\n", "begin taos_insert_lines", tidBuf);
+  int64_t begin = getTimeInUs();
+  int32_t code = taos_insert_lines(insertArgs->taos, insertArgs->lines, insertArgs->numLines);
+  int64_t end = getTimeInUs();
+  printf("code: %d, %s. time used:%"PRId64", thread: 0x%s\n", code, tstrerror(code), end - begin, tidBuf);
+  return NULL;
+}
+
 int main(int argc, char* argv[]) {
   TAOS_RES*   result;
   const char* host = "127.0.0.1";
@@ -60,25 +86,77 @@ int main(int argc, char* argv[]) {
   int64_t ts = ct * 1000;
   char* lineFormat = "sta%d,t0=true,t1=127i8,t2=32767i16,t3=%di32,t4=9223372036854775807i64,t9=11.12345f32,t10=22.123456789f64,t11=\"binaryTagValue\",t12=L\"ncharTagValue\" c0=true,c1=127i8,c2=32767i16,c3=2147483647i32,c4=9223372036854775807i64,c5=254u8,c6=32770u16,c7=2147483699u32,c8=9223372036854775899u64,c9=11.12345f32,c10=22.123456789f64,c11=\"binaryValue\",c12=L\"ncharValue\" %lldms";
 
-  char** lines = calloc(numSuperTables * numChildTables * numRowsPerChildTable, sizeof(char*));
-  int    l = 0;
-  for (int i = 0; i < numSuperTables; ++i) {
-    for (int j = 0; j < numChildTables; ++j) {
-      for (int k = 0; k < numRowsPerChildTable; ++k) {
-        char* line = calloc(512, 1);
-        snprintf(line, 512, lineFormat, i, j, ts + 10 * l);
-        lines[l] = line;
-        ++l;
+  {
+    char** linesStb = calloc(numSuperTables, sizeof(char*));
+    for (int i = 0; i < numSuperTables; i++) {
+      char* lineStb = calloc(512, 1);
+      snprintf(lineStb, 512, lineFormat, i,
+               numThreads * numSuperTables * numChildTablesPerThread,
+               ts + numThreads * numSuperTables * numChildTablesPerThread * numRowsPerChildTable);
+      linesStb[i] = lineStb;
+    }
+    SThreadInsertArgs args = {0};
+    args.taos = taos;
+    args.lines = linesStb;
+    args.numLines = numSuperTables;
+    insertLines(&args);
+    for (int i = 0; i < numSuperTables; ++i) {
+      free(linesStb[i]);
+    }
+    free(linesStb);
+  }
+
+  printf("generate lines...\n");
+  char*** linesThread = calloc(numThreads, sizeof(char**));
+  for (int i = 0; i < numThreads; ++i) {
+    char** lines = calloc(numSuperTables * numChildTablesPerThread * numRowsPerChildTable, sizeof(char*));
+    linesThread[i] = lines;
+  }
+
+  for (int t = 0; t < numThreads; ++t) {
+    int l = 0;
+    char** lines = linesThread[t];
+    for (int i = 0; i < numSuperTables; ++i) {
+      for (int j = 0; j < numChildTablesPerThread; ++j) {
+        for (int k = 0; k < numRowsPerChildTable; ++k) {
+          int stIdx = i;
+          int ctIdx = t*numSuperTables*numChildTablesPerThread + j;
+          char* line = calloc(512, 1);
+          snprintf(line, 512, lineFormat, stIdx, ctIdx, ts + 10 * l);
+          lines[l] = line;
+          ++l;
+        }
       }
     }
   }
-  //shuffle(lines, numSuperTables * numChildTables * numRowsPerChildTable);
 
-  printf("%s\n", "begin taos_insert_lines");
-  int64_t begin = getTimeInUs();
-  int32_t code = taos_insert_lines(taos, lines, numSuperTables * numChildTables * numRowsPerChildTable);
-  int64_t end = getTimeInUs();
-  printf("code: %d, %s. time used: %" PRId64 "\n", code, tstrerror(code), end - begin);
+  printf("shuffle lines...\n");
+  for (int t = 0; t < numThreads; ++t) {
+    shuffle(linesThread[t], numSuperTables * numChildTablesPerThread * numRowsPerChildTable);
+  }
+
+  printf("begin multi-thread insertion...");
+  pthread_t* tids = calloc(numThreads, sizeof(pthread_t));
+  SThreadInsertArgs* argsThread = calloc(numThreads, sizeof(SThreadInsertArgs));
+  for (int i=0; i < numThreads; ++i) {
+    argsThread[i].lines = linesThread[i];
+    argsThread[i].taos = taos;
+    argsThread[i].numLines = numSuperTables * numChildTablesPerThread * numRowsPerChildTable;
+    pthread_create(tids+i, NULL, insertLines, argsThread+i);
+  }
+
+
+  for (int i = 0; i < numThreads; ++i) {
+    pthread_join(tids[i], NULL);
+  }
+
+  free(argsThread);
+  free(tids);
+  for (int i = 0; i < numThreads; ++i) {
+    free(linesThread[i]);
+  }
+  free(linesThread);
 
+  taos_close(taos);
   return 0;
 }