diff --git a/src/client/src/tscUtil.c b/src/client/src/tscUtil.c
index 086dcfb29b225eda391834604ead57942700f712..60238c63fc7c80e3ce74f77086ee129a0967bd29 100644
--- a/src/client/src/tscUtil.c
+++ b/src/client/src/tscUtil.c
@@ -5221,7 +5221,7 @@ char* parseTagDatatoJson(void *p){
 
   int16_t nCols = kvRowNCols(p);
   ASSERT(nCols%2 == 1);
-  char tagJsonKey[TSDB_MAX_TAGS_LEN] = {0};
+  char tagJsonKey[TSDB_MAX_JSON_KEY_LEN + 1] = {0};
   for (int j = 0; j < nCols; ++j) {
     SColIdx * pColIdx = kvRowColIdxAt(p, j);
     void* val = (kvRowColVal(p, pColIdx));
@@ -5230,13 +5230,10 @@ char* parseTagDatatoJson(void *p){
       ASSERT(jsonVal == TSDB_DATA_BINARY_PLACEHOLDER);
       continue;
     }
-    if (j%2 != 0) { // json key
-      memset(tagJsonKey, 0, TSDB_MAX_TAGS_LEN);
-      int32_t length = taosUcs4ToMbs(varDataVal(val), varDataLen(val), tagJsonKey);
-      if (length == 0) {
-        tscError("charset:%s to %s. val:%s convert json key failed.", DEFAULT_UNICODE_ENCODEC, tsCharset, (char*)val);
-        goto end;
-      }
+    if (j%2 != 0) { // json key  encode by binary
+      ASSERT(varDataLen(val) <= TSDB_MAX_JSON_KEY_LEN);
+      memset(tagJsonKey, 0, sizeof(tagJsonKey));
+      memcpy(tagJsonKey, varDataVal(val), varDataLen(val));
     }else{  // json value
       char tagJsonValue[TSDB_MAX_TAGS_LEN] = {0};
       char* realData = POINTER_SHIFT(val, CHAR_BYTES);
diff --git a/src/common/inc/tglobal.h b/src/common/inc/tglobal.h
index 0b682ca5738744b371fda6f3e512c416167d055f..beeb4e8b243e21e33f4162b07ec218c40e4029f9 100644
--- a/src/common/inc/tglobal.h
+++ b/src/common/inc/tglobal.h
@@ -229,8 +229,6 @@ extern int8_t tsDeadLockKillQuery;
 
 // schemaless
 extern char tsDefaultJSONStrType[];
-#define JSON_TYPE_BINARY (strcasecmp(tsDefaultJSONStrType, "binary") == 0)
-#define JSON_TYPE_NCHAR (strcasecmp(tsDefaultJSONStrType, "nchar") == 0)
 
 typedef struct {
   char dir[TSDB_FILENAME_LEN];