diff --git a/paddlespeech/t2s/exps/inference.py b/paddlespeech/t2s/exps/inference.py
index 3edc4b63b..99d147958 100644
--- a/paddlespeech/t2s/exps/inference.py
+++ b/paddlespeech/t2s/exps/inference.py
@@ -12,6 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import argparse
+import os
 from pathlib import Path
 
 import paddle
@@ -126,6 +127,12 @@ def main():
 
     paddle.set_device(args.device)
 
+    # model_suffix
+    if os.path.exists(args.am + ".json"):
+        model_suffix = ".json"
+    else:
+        model_suffix = ".pdmodel"
+
     # frontend
     frontend = get_frontend(
         lang=args.lang,
@@ -135,7 +142,7 @@ def main():
     # am_predictor
     am_predictor = get_predictor(
         model_dir=args.inference_dir,
-        model_file=args.am + ".pdmodel",
+        model_file=args.am + model_suffix,
         params_file=args.am + ".pdiparams",
         device=args.device,
         use_trt=args.use_trt,
@@ -148,7 +155,7 @@ def main():
     # voc_predictor
     voc_predictor = get_predictor(
         model_dir=args.inference_dir,
-        model_file=args.voc + ".pdmodel",
+        model_file=args.voc + model_suffix,
         params_file=args.voc + ".pdiparams",
         device=args.device,
         use_trt=args.use_trt,