diff --git a/fastNLP/core/field.py b/fastNLP/core/field.py
index b57b9bb6..ebf8f2ea 100644
--- a/fastNLP/core/field.py
+++ b/fastNLP/core/field.py
@@ -93,5 +93,35 @@ class LabelField(Field):
             return torch.LongTensor([self._index])
 
 
+class SeqLabelField(Field):
+    def __init__(self, label_seq, is_target=True):
+        super(SeqLabelField, self).__init__(is_target)
+        self.label_seq = label_seq
+        self._index = None
+    
+    def get_length(self):
+        return len(self.label_seq)
+
+    def index(self, vocab):
+        if self._index is None:
+            self._index = [vocab[c] for c in self.label_seq]
+        return self._index
+
+    def to_tensor(self, padding_length):
+        pads = [0] * (padding_length - self.get_length())
+        if self._index is None:
+            if self.get_length() == 0:
+                return pads
+            elif isinstance(self.label_seq[0], int):
+                return torch.LongTensor(self.label_seq + pads)
+            elif isinstance(self.label_seq[0], str):
+                raise RuntimeError("Field {} not indexed. Call index method.".format(self.label))
+            else:
+                raise RuntimeError(
+                    "Not support type for SeqLabelField. Expect str or int, got {}.".format(type(self.label)))
+        else:
+            return torch.LongTensor(self._index + pads)
+
+
 if __name__ == "__main__":
     tf = TextField("test the code".split(), is_target=False)
diff --git a/fastNLP/core/vocabulary.py b/fastNLP/core/vocabulary.py
index d2ed4564..77b27b92 100644
--- a/fastNLP/core/vocabulary.py
+++ b/fastNLP/core/vocabulary.py
@@ -126,12 +126,14 @@ class Vocabulary(object):
         """
         return self[w]
 
+    @property
     @check_build_vocab
     def unknown_idx(self):
         if self.unknown_label is None:
             return None
         return self.word2idx[self.unknown_label]
 
+    @property
     @check_build_vocab
     def padding_idx(self):
         if self.padding_label is None:
diff --git a/fastNLP/loader/embed_loader.py b/fastNLP/loader/embed_loader.py
index 6de83cee..b44c9851 100644
--- a/fastNLP/loader/embed_loader.py
+++ b/fastNLP/loader/embed_loader.py
@@ -1,7 +1,7 @@
 import _pickle
 import os
 
-import numpy as np
+import torch
 
 from fastNLP.loader.base_loader import BaseLoader
 from fastNLP.core.vocabulary import Vocabulary
@@ -30,7 +30,7 @@ class EmbedLoader(BaseLoader):
             for line in f:
                 line = list(filter(lambda w: len(w)>0, line.strip().split(' ')))
                 if len(line) > 0:
-                    emb[line[0]] = np.array(list(map(float, line[1:])))
+                    emb[line[0]] = torch.Tensor(list(map(float, line[1:])))
         return emb
     
     @staticmethod
@@ -62,8 +62,8 @@ class EmbedLoader(BaseLoader):
         # If the embedding pickle exists, load it and return.
         if os.path.exists(emb_pkl):
             with open(emb_pkl, "rb") as f:
-                embedding_np = _pickle.load(f)
-            return embedding_np
+                embedding_np, vocab = _pickle.load(f)
+            return embedding_np, vocab
         # Otherwise, load the pre-trained embedding.
         pretrain = EmbedLoader._load_pretrain(emb_file, emb_type)
         if vocab is None:
@@ -71,7 +71,7 @@ class EmbedLoader(BaseLoader):
             vocab = Vocabulary()
             for w in pretrain.keys():
                 vocab.update(w)
-        embedding_np = np.random.uniform(-1, 1, size=(len(vocab), emb_dim))
+        embedding_np = torch.randn(len(vocab), emb_dim)
         for w, v in pretrain.items():
             if len(v.shape) > 1 or emb_dim != v.shape[0]:
                 raise ValueError('pretrian embedding dim is {}, dismatching required {}'.format(v.shape, (emb_dim,)))
@@ -80,5 +80,5 @@ class EmbedLoader(BaseLoader):
 
         # save and return the result
         with open(emb_pkl, "wb") as f:
-            _pickle.dump(embedding_np, f)
+            _pickle.dump((embedding_np, vocab), f)
         return embedding_np, vocab