diff --git a/apps/emqx_management/src/emqx_mgmt_api_trace.erl b/apps/emqx_management/src/emqx_mgmt_api_trace.erl
index 4bdf225fd..17895786b 100644
--- a/apps/emqx_management/src/emqx_mgmt_api_trace.erl
+++ b/apps/emqx_management/src/emqx_mgmt_api_trace.erl
@@ -84,11 +84,16 @@ schema("/trace") ->
                 200 => hoconsc:ref(trace),
                 400 => emqx_dashboard_swagger:error_codes(
                     [
-                        'ALREADY_EXISTS',
-                        'DUPLICATE_CONDITION',
                         'INVALID_PARAMS'
                     ],
-                    <<"trace name already exists">>
+                    <<"invalid trace params">>
+                ),
+                409 => emqx_dashboard_swagger:error_codes(
+                    [
+                        'ALREADY_EXISTS',
+                        'DUPLICATE_CONDITION'
+                    ],
+                    <<"trace already exists">>
                 )
             }
         },
@@ -392,12 +397,12 @@ trace(post, #{body := Param}) ->
         {ok, Trace0} ->
             {200, format_trace(Trace0)};
         {error, {already_existed, Name}} ->
-            {400, #{
+            {409, #{
                 code => 'ALREADY_EXISTS',
                 message => ?TO_BIN([Name, " Already Exists"])
             }};
         {error, {duplicate_condition, Name}} ->
-            {400, #{
+            {409, #{
                 code => 'DUPLICATE_CONDITION',
                 message => ?TO_BIN([Name, " Duplication Condition"])
             }};
diff --git a/apps/emqx_management/test/emqx_mgmt_api_trace_SUITE.erl b/apps/emqx_management/test/emqx_mgmt_api_trace_SUITE.erl
index 68c998c47..d73cb79fd 100644
--- a/apps/emqx_management/test/emqx_mgmt_api_trace_SUITE.erl
+++ b/apps/emqx_management/test/emqx_mgmt_api_trace_SUITE.erl
@@ -149,7 +149,7 @@ t_create_failed(_Config) ->
     {ok, Create} = request_api(post, api_path("trace"), Header, [GoodName | Trace]),
     ?assertMatch(#{<<"name">> := <<"test-name-0">>}, json(Create)),
     ?assertMatch(
-        {error, {"HTTP/1.1", 400, _}, _},
+        {error, {"HTTP/1.1", 409, _}, _},
         request_api(post, api_path("trace"), Header, [GoodName | Trace])
     ),
 
@@ -171,6 +171,16 @@ t_create_failed(_Config) ->
         {error, {"HTTP/1.1", 400, _}, _},
         request_api(post, api_path("trace"), Header, [GoodName1 | Trace])
     ),
+    %% clear
+    ?assertMatch({ok, _}, request_api(delete, api_path("trace"), Header, [])),
+    {ok, Create} = request_api(post, api_path("trace"), Header, [GoodName | Trace]),
+    %% new name but same trace
+    GoodName2 = {<<"name">>, <<"test-name-1">>},
+    ?assertMatch(
+        {error, {"HTTP/1.1", 409, _}, _},
+        request_api(post, api_path("trace"), Header, [GoodName2 | Trace])
+    ),
+
     unload(),
     emqx_trace:clear(),
     ok.
diff --git a/changes/v5.0.12-en.md b/changes/v5.0.12-en.md
index d206774f4..97992568f 100644
--- a/changes/v5.0.12-en.md
+++ b/changes/v5.0.12-en.md
@@ -49,4 +49,6 @@ Please note, the request body of `/bridges` API to configure MQTT brdige is chan
 - Fix shadowing `'client.authenticate'` callbacks by `emqx_authenticator`. Now `emqx_authenticator`
   passes execution to the further callbacks if none of the authenticators matches [#9496](https://github.com/emqx/emqx/pull/9496).
 
-- Return `400` if query param `node` is not a known in `/trace/:id/download?node={node}` [#9478](https://github.com/emqx/emqx/pull/9478).
+- Return `400` if query param `node` is not a known node in `/trace/:id/download?node={node}` [#9478](https://github.com/emqx/emqx/pull/9478).
+
+- `POST /traces` to return `409` in case of duplicate [#9494](https://github.com/emqx/emqx/pull/9494).
diff --git a/changes/v5.0.12-zh.md b/changes/v5.0.12-zh.md
index 919d76784..a0d67424e 100644
--- a/changes/v5.0.12-zh.md
+++ b/changes/v5.0.12-zh.md
@@ -47,4 +47,6 @@ v5.0.11 或更早版本创建的配置文件，在新版本中会被自动转换
 
 - 通过 `emqx_authenticator` 修复隐藏 `'client.authenticate'` 回调。 现在 `emqx_authenticator` 如果没有任何验证器匹配，则将执行传递给进一步的回调 [#9496](https://github.com/emqx/emqx/pull/9496)。
 
-- 如果在调用 `/trace/:id/download?node={node}` 时，`node` 不存在，则会返回 `400` [#9478](https://github.com/emqx/emqx/pull/9478).
+- 如果在调用 `/trace/:id/download?node={node}` 时，`node` 不存在，则会返回 `400` [#9478](https://github.com/emqx/emqx/pull/9478)。
+
+- 当重复调用 `POST /traces` 时，将会返回 `409` ，而不再是 `400` [#9494](https://github.com/emqx/emqx/pull/9494)。