diff --git a/demo/sentiment/train_v2.py b/demo/sentiment/train_v2.py
index 3d595fad30b71ac259cbb14639e0c6792dc8481d..0fa74948533b4362a7a9206e7a787cf217ca5ca2 100644
--- a/demo/sentiment/train_v2.py
+++ b/demo/sentiment/train_v2.py
@@ -2,10 +2,11 @@ import sys
 from os.path import join as join_path
 import paddle.trainer_config_helpers.attrs as attrs
 from paddle.trainer_config_helpers.poolings import MaxPooling
-import paddle.v2 as paddle
 import paddle.v2.layer as layer
 import paddle.v2.activation as activation
 import paddle.v2.data_type as data_type
+import paddle.v2.dataset.imdb as imdb
+import paddle.v2 as paddle
 
 
 def sequence_conv_pool(input,
@@ -189,36 +190,15 @@ def stacked_lstm_net(input_dim,
     return cost
 
 
-def data_reader(data_file, dict_file):
-    def reader():
-        with open(dict_file, 'r') as fdict, open(data_file, 'r') as fdata:
-            dictionary = dict()
-            for i, line in enumerate(fdict):
-                dictionary[line.split('\t')[0]] = i
-
-            for line_count, line in enumerate(fdata):
-                label, comment = line.strip().split('\t\t')
-                label = int(label)
-                words = comment.split()
-                word_slot = [dictionary[w] for w in words if w in dictionary]
-                yield (word_slot, label)
-
-    return reader
-
-
 if __name__ == '__main__':
-    # data file
-    train_file = "./data/pre-imdb/train_part_000"
-    test_file = "./data/pre-imdb/test_part_000"
-    dict_file = "./data/pre-imdb/dict.txt"
-    labels = "./data/pre-imdb/labels.list"
-
     # init
     paddle.init(use_gpu=True, trainer_count=4)
 
     # network config
-    dict_dim = len(open(dict_file).readlines())
-    class_dim = len(open(labels).readlines())
+    print 'load dictionary...'
+    word_dict = imdb.word_dict()
+    dict_dim = len(word_dict)
+    class_dim = 2
 
     # Please choose the way to build the network
     # by uncommenting the corresponding line.
@@ -246,7 +226,7 @@ if __name__ == '__main__':
         if isinstance(event, paddle.event.EndPass):
             result = trainer.test(
                 reader=paddle.reader.batched(
-                    data_reader(test_file, dict_file), batch_size=128),
+                    lambda: imdb.test(word_dict), batch_size=128),
                 reader_dict={'word': 0,
                              'label': 1})
             print "\nTest with Pass %d, %s" % (event.pass_id, result.metrics)
@@ -259,8 +239,8 @@ if __name__ == '__main__':
     trainer.train(
         reader=paddle.reader.batched(
             paddle.reader.shuffle(
-                data_reader(train_file, dict_file), buf_size=4096),
-            batch_size=128),
+                lambda: imdb.train(word_dict), buf_size=1000),
+            batch_size=100),
         event_handler=event_handler,
         reader_dict={'word': 0,
                      'label': 1},
diff --git a/python/paddle/v2/dataset/imdb.py b/python/paddle/v2/dataset/imdb.py
index 433e37380f840f5b7ff619a5f64b99d2ad724b17..db388be1e06d636ef33ec1c2ecf2408e5e1d4d59 100644
--- a/python/paddle/v2/dataset/imdb.py
+++ b/python/paddle/v2/dataset/imdb.py
@@ -118,3 +118,8 @@ def test(word_idx):
     return reader_creator(
         re.compile("aclImdb/test/pos/.*\.txt$"),
         re.compile("aclImdb/test/neg/.*\.txt$"), word_idx, 1000)
+
+
+def word_dict():
+    return build_dict(
+        re.compile("aclImdb/((train)|(test))/((pos)|(neg))/.*\.txt$"), 150)