diff --git a/fastNLP/io/dataset_loader.py b/fastNLP/io/dataset_loader.py
index bb5e2f64..a9babce5 100644
--- a/fastNLP/io/dataset_loader.py
+++ b/fastNLP/io/dataset_loader.py
@@ -330,7 +330,10 @@ class JsonLoader(DataSetLoader):
     def load(self, path):
         ds = DataSet()
         for idx, d in _read_json(path, fields=self.fields_list, dropna=self.dropna):
-            ins = {self.fields[k]:v for k,v in d.items()}
+            if self.fields:
+                ins = {self.fields[k]:v for k,v in d.items()}
+            else:
+                ins = d
             ds.append(Instance(**ins))
         return ds
 
diff --git a/test/core/test_batch.py b/test/core/test_batch.py
index 2bf2dcea..072f7c83 100644
--- a/test/core/test_batch.py
+++ b/test/core/test_batch.py
@@ -142,13 +142,12 @@ class TestCase1(unittest.TestCase):
 
     def test_sequential_batch(self):
         batch_size = 32
-        pause_seconds = 0.01
         num_samples = 1000
         dataset = generate_fake_dataset(num_samples)
 
         batch = Batch(dataset, batch_size=batch_size, sampler=SequentialSampler())
         for batch_x, batch_y in batch:
-            time.sleep(pause_seconds)
+            pass
 
     """
     def test_multi_workers_batch(self):
diff --git a/test/core/test_metrics.py b/test/core/test_metrics.py
index 3f37c495..d4422ec4 100644
--- a/test/core/test_metrics.py
+++ b/test/core/test_metrics.py
@@ -132,6 +132,19 @@ class TestAccuracyMetric(unittest.TestCase):
             return
         self.assertTrue(True, False), "No exception catches."
 
+    def test_seq_len(self):
+        N = 256
+        seq_len = torch.zeros(N).long()
+        seq_len[0] = 2
+        pred = {'pred': torch.ones(N, 2)}
+        target = {'target': torch.ones(N, 2), 'seq_len': seq_len}
+        metric = AccuracyMetric()
+        metric(pred_dict=pred, target_dict=target)
+        self.assertDictEqual(metric.get_metric(), {'acc': 1.})
+        seq_len[1:] = 1
+        metric(pred_dict=pred, target_dict=target)
+        self.assertDictEqual(metric.get_metric(), {'acc': 1.})
+
 class SpanF1PreRecMetric(unittest.TestCase):
     def test_case1(self):
         from fastNLP.core.metrics import _bmes_tag_to_spans
diff --git a/test/models/test_biaffine_parser.py b/test/models/test_biaffine_parser.py
index 5d6c2102..918f0fd9 100644
--- a/test/models/test_biaffine_parser.py
+++ b/test/models/test_biaffine_parser.py
@@ -77,13 +77,13 @@ def init_data():
 class TestBiaffineParser(unittest.TestCase):
     def test_train(self):
         ds, v1, v2, v3 = init_data()
-        model = BiaffineParser(word_vocab_size=len(v1), word_emb_dim=30,
+        model = BiaffineParser(init_embed=(len(v1), 30),
                                pos_vocab_size=len(v2), pos_emb_dim=30,
                                num_label=len(v3), encoder='var-lstm')
         trainer = fastNLP.Trainer(model=model, train_data=ds, dev_data=ds,
                                   loss=ParserLoss(), metrics=ParserMetric(), metric_key='UAS',
                                   batch_size=1, validate_every=10,
-                                  n_epochs=10, use_cuda=False, use_tqdm=False)
+                                  n_epochs=10, use_tqdm=False)
         trainer.train(load_best_model=False)