diff --git a/include/neuron/define.h b/include/neuron/define.h
index 74df208f..c07ba413 100644
--- a/include/neuron/define.h
+++ b/include/neuron/define.h
@@ -31,7 +31,7 @@
 #define NEU_GET_VERSION_FIX(V) ((0x000000ff & V))
 #define NEU_VERSION(MAJOR, MINOR, FIX) ((MAJOR << 16) | (MINOR << 8) | FIX)
 
-#define NEU_TAG_NAME_LEN 64
+#define NEU_TAG_NAME_LEN 128
 #define NEU_TAG_ADDRESS_LEN 128
 #define NEU_TAG_DESCRIPTION_LEN 128
 #define NEU_GROUP_MAX_PER_NODE 512
diff --git a/tests/ft/tag/test_tag.py b/tests/ft/tag/test_tag.py
index 2add729a..41fc6172 100644
--- a/tests/ft/tag/test_tag.py
+++ b/tests/ft/tag/test_tag.py
@@ -457,4 +457,30 @@ class TestLog:
         )
 
         assert 409 == response.status_code
-        assert NEU_ERR_TAG_NAME_CONFLICT == response.json()['error']
\ No newline at end of file
+        assert NEU_ERR_TAG_NAME_CONFLICT == response.json()['error']
+
+    @description(given="tag name length exceeds 128", when="adding", then="add failed")
+    def test_adding_tag_name_exceeds_128(self):
+        response = api.add_gtags(
+            node='modbus-tcp-tag-test', 
+            groups=[{"group": "group","interval": 3000,
+                     "tags": [{
+                            "name": "Lt7Pa5Q0tKJN2gL3WiYJLnaFzqBq5q5xyJ1vYHxyf2j0IZR7y3RBYxXGQBHwV7dEzD7lIcF1yX9aR3vH8leYxXxHUILk2eVqQBlaQLaROZt9yZ9xQNxKkfy5mySHb79",
+                            "address": "1!400001",
+                            "attribute": 3,
+                            "type": 3,
+                            "decimal": 0.01}]}])
+        assert 200 == response.status_code
+        assert NEU_ERR_SUCCESS == response.json()['error']
+
+        response = api.add_gtags(
+            node='modbus-tcp-tag-test', 
+            groups=[{"group": "group","interval": 3000,
+                     "tags": [{
+                            "name": "Lt7Pa5Q0tKJN2gL3WiYJLnaFzqBq5q5xyJ1vYHxyf2j0IZR7y3RBYxXGQBHwV7dEzD7lIcF1yX9aR3vH8leYxXxHUILk2eVqQBlaQLaROZt9yZ9xQNxKkfy5mySHb79Y8",
+                            "address": "1!400001",
+                            "attribute": 3,
+                            "type": 3,
+                            "decimal": 0.01}]}])
+        assert 400 == response.status_code
+        assert NEU_ERR_TAG_NAME_TOO_LONG == response.json()['error']
\ No newline at end of file