diff --git a/qlib/contrib/model/pytorch_tra.py b/qlib/contrib/model/pytorch_tra.py
index d150466c1..f6c659533 100644
--- a/qlib/contrib/model/pytorch_tra.py
+++ b/qlib/contrib/model/pytorch_tra.py
@@ -352,7 +352,8 @@ class TRAModel(Model):
                     "model": copy.deepcopy(self.model.state_dict()),
                     "tra": copy.deepcopy(self.tra.state_dict()),
                 }
-                torch.save(best_params, self.logdir + "/model.bin")
+                if self.logdir is not None:
+                    torch.save(best_params, self.logdir + "/model.bin")
             else:
                 stop_rounds += 1
                 if stop_rounds >= self.early_stop: