diff --git a/python/paddle/v2/dataset/cifar.py b/python/paddle/v2/dataset/cifar.py
index 81af0a8e66a44a3476206147684d81bcac1be372..95984d980dc5e8576a8bce6aca67b89bbea921bd 100644
--- a/python/paddle/v2/dataset/cifar.py
+++ b/python/paddle/v2/dataset/cifar.py
@@ -31,7 +31,7 @@ images per class.
 import cPickle
 import itertools
 import numpy
-from common import download
+import paddle.v2.dataset.common
 import tarfile
 
 __all__ = ['train100', 'test100', 'train10', 'test10']
@@ -75,7 +75,8 @@ def train100():
     :rtype: callable
     """
     return reader_creator(
-        download(CIFAR100_URL, 'cifar', CIFAR100_MD5), 'train')
+        paddle.v2.dataset.common.download(CIFAR100_URL, 'cifar', CIFAR100_MD5),
+        'train')
 
 
 def test100():
@@ -88,7 +89,9 @@ def test100():
     :return: Test reader creator.
     :rtype: callable
     """
-    return reader_creator(download(CIFAR100_URL, 'cifar', CIFAR100_MD5), 'test')
+    return reader_creator(
+        paddle.v2.dataset.common.download(CIFAR100_URL, 'cifar', CIFAR100_MD5),
+        'test')
 
 
 def train10():
@@ -102,7 +105,8 @@ def train10():
     :rtype: callable
     """
     return reader_creator(
-        download(CIFAR10_URL, 'cifar', CIFAR10_MD5), 'data_batch')
+        paddle.v2.dataset.common.download(CIFAR10_URL, 'cifar', CIFAR10_MD5),
+        'data_batch')
 
 
 def test10():
@@ -116,9 +120,20 @@ def test10():
     :rtype: callable
     """
     return reader_creator(
-        download(CIFAR10_URL, 'cifar', CIFAR10_MD5), 'test_batch')
+        paddle.v2.dataset.common.download(CIFAR10_URL, 'cifar', CIFAR10_MD5),
+        'test_batch')
 
 
 def fetch():
-    download(CIFAR10_URL, 'cifar', CIFAR10_MD5)
-    download(CIFAR100_URL, 'cifar', CIFAR100_MD5)
+    paddle.v2.dataset.common.download(CIFAR10_URL, 'cifar', CIFAR10_MD5)
+    paddle.v2.dataset.common.download(CIFAR100_URL, 'cifar', CIFAR100_MD5)
+
+
+def convert(path):
+    """
+    Converts dataset to recordio format
+    """
+    paddle.v2.dataset.common.convert(path, train100(), 10, "cifar_train100")
+    paddle.v2.dataset.common.convert(path, test100(), 10, "cifar_test100")
+    paddle.v2.dataset.common.convert(path, train10(), 10, "cifar_train10")
+    paddle.v2.dataset.common.convert(path, test10(), 10, "cifar_test10")
diff --git a/python/paddle/v2/dataset/common.py b/python/paddle/v2/dataset/common.py
index 72894c24b16162f41db729d8bcabf09cd5510922..4a2eb59c340f5d0d3818170e56d730330e0bab29 100644
--- a/python/paddle/v2/dataset/common.py
+++ b/python/paddle/v2/dataset/common.py
@@ -23,7 +23,10 @@ import paddle.v2.dataset
 import cPickle
 import glob
 
-__all__ = ['DATA_HOME', 'download', 'md5file', 'split', 'cluster_files_reader']
+__all__ = [
+    'DATA_HOME', 'download', 'md5file', 'split', 'cluster_files_reader',
+    'convert'
+]
 
 DATA_HOME = os.path.expanduser('~/.cache/paddle/dataset')
 
diff --git a/python/paddle/v2/dataset/conll05.py b/python/paddle/v2/dataset/conll05.py
index 12d648bf6557ed6e437320e56a80294abac29f18..d4c2276b1b32c1ba4dd667483b22120ff42155d9 100644
--- a/python/paddle/v2/dataset/conll05.py
+++ b/python/paddle/v2/dataset/conll05.py
@@ -23,7 +23,7 @@ to initialize SRL model.
 import tarfile
 import gzip
 import itertools
-from common import download
+import paddle.v2.dataset.common
 
 __all__ = ['test, get_dict', 'get_embedding']
 
@@ -182,9 +182,15 @@ def get_dict():
     """
     Get the word, verb and label dictionary of Wikipedia corpus.
     """
-    word_dict = load_dict(download(WORDDICT_URL, 'conll05st', WORDDICT_MD5))
-    verb_dict = load_dict(download(VERBDICT_URL, 'conll05st', VERBDICT_MD5))
-    label_dict = load_dict(download(TRGDICT_URL, 'conll05st', TRGDICT_MD5))
+    word_dict = load_dict(
+        paddle.v2.dataset.common.download(WORDDICT_URL, 'conll05st',
+                                          WORDDICT_MD5))
+    verb_dict = load_dict(
+        paddle.v2.dataset.common.download(VERBDICT_URL, 'conll05st',
+                                          VERBDICT_MD5))
+    label_dict = load_dict(
+        paddle.v2.dataset.common.download(TRGDICT_URL, 'conll05st',
+                                          TRGDICT_MD5))
     return word_dict, verb_dict, label_dict
 
 
@@ -192,7 +198,7 @@ def get_embedding():
     """
     Get the trained word vector based on Wikipedia corpus.
     """
-    return download(EMB_URL, 'conll05st', EMB_MD5)
+    return paddle.v2.dataset.common.download(EMB_URL, 'conll05st', EMB_MD5)
 
 
 def test():
@@ -209,15 +215,23 @@ def test():
     """
     word_dict, verb_dict, label_dict = get_dict()
     reader = corpus_reader(
-        download(DATA_URL, 'conll05st', DATA_MD5),
+        paddle.v2.dataset.common.download(DATA_URL, 'conll05st', DATA_MD5),
         words_name='conll05st-release/test.wsj/words/test.wsj.words.gz',
         props_name='conll05st-release/test.wsj/props/test.wsj.props.gz')
     return reader_creator(reader, word_dict, verb_dict, label_dict)
 
 
 def fetch():
-    download(WORDDICT_URL, 'conll05st', WORDDICT_MD5)
-    download(VERBDICT_URL, 'conll05st', VERBDICT_MD5)
-    download(TRGDICT_URL, 'conll05st', TRGDICT_MD5)
-    download(EMB_URL, 'conll05st', EMB_MD5)
-    download(DATA_URL, 'conll05st', DATA_MD5)
+    paddle.v2.dataset.common.download(WORDDICT_URL, 'conll05st', WORDDICT_MD5)
+    paddle.v2.dataset.common.download(VERBDICT_URL, 'conll05st', VERBDICT_MD5)
+    paddle.v2.dataset.common.download(TRGDICT_URL, 'conll05st', TRGDICT_MD5)
+    paddle.v2.dataset.common.download(EMB_URL, 'conll05st', EMB_MD5)
+    paddle.v2.dataset.common.download(DATA_URL, 'conll05st', DATA_MD5)
+
+
+def convert():
+    """
+    Converts dataset to recordio format
+    """
+    paddle.v2.dataset.common.convert(path, test(), 10, "conl105_train")
+    paddle.v2.dataset.common.convert(path, test(), 10, "conl105_test")
diff --git a/python/paddle/v2/dataset/imdb.py b/python/paddle/v2/dataset/imdb.py
index 5dc5abfe53d90ec3adc9a27a49ed086953146497..d939bc30653496ba234f1e2f14fe815df0699c04 100644
--- a/python/paddle/v2/dataset/imdb.py
+++ b/python/paddle/v2/dataset/imdb.py
@@ -166,3 +166,14 @@ def word_dict():
 
 def fetch():
     paddle.v2.dataset.common.download(URL, 'imdb', MD5)
+
+
+def convert():
+    """
+    Converts dataset to recordio format
+    """
+    word_dict = ds.imdb.word_dict()
+    paddle.v2.dataset.common.convert(path, lambda: train(word_dict), 10,
+                                     "imdb_train")
+    paddle.v2.dataset.common.convert(path, lambda: test(word_dict), 10,
+                                     "imdb_test")
diff --git a/python/paddle/v2/dataset/imikolov.py b/python/paddle/v2/dataset/imikolov.py
index dd3a4552d2e1a2b00dde5ddb7ac1d78445bdca51..034f58c2c809045ec8cff3d86efcfcda8172c405 100644
--- a/python/paddle/v2/dataset/imikolov.py
+++ b/python/paddle/v2/dataset/imikolov.py
@@ -18,7 +18,7 @@ This module will download dataset from
 http://www.fit.vutbr.cz/~imikolov/rnnlm/ and parse training set and test set
 into paddle reader creators.
 """
-import paddle.v2.dataset.common
+import paddle.v2.dataset.common as common
 import collections
 import tarfile
 
@@ -145,4 +145,14 @@ def test(word_idx, n, data_type=DataType.NGRAM):
 
 
 def fetch():
-    paddle.v2.dataset.common.download(URL, "imikolov", MD5)
+    common.download(URL, "imikolov", MD5)
+
+
+def convert(path):
+    """
+    Converts dataset to recordio format
+    """
+    N = 5
+    word_dict = build_dict()
+    common.convert(path, train(word_dict, N), 10, "imikolov_train")
+    common.convert(path, test(word_dict, N), 10, "imikolov_test")
diff --git a/python/paddle/v2/dataset/mnist.py b/python/paddle/v2/dataset/mnist.py
index 435556b2921b7976bbc61160ce3812949981c9e7..92d7f69b8dfd4795e4a5c680dcc1fe9bb26f7e2b 100644
--- a/python/paddle/v2/dataset/mnist.py
+++ b/python/paddle/v2/dataset/mnist.py
@@ -113,3 +113,11 @@ def fetch():
     paddle.v2.dataset.common.download(TRAIN_LABEL_URL, 'mnist', TRAIN_LABEL_MD5)
     paddle.v2.dataset.common.download(TEST_IMAGE_URL, 'mnist', TEST_IMAGE_MD5)
     paddle.v2.dataset.common.download(TEST_LABEL_URL, 'mnist', TRAIN_LABEL_MD5)
+
+
+def convert(path):
+    """
+    Converts dataset to recordio format
+    """
+    paddle.v2.dataset.common.convert(path, train(), 10, "minist_train")
+    paddle.v2.dataset.common.convert(path, test(), 10, "minist_test")
diff --git a/python/paddle/v2/dataset/movielens.py b/python/paddle/v2/dataset/movielens.py
index 837a85912663826f0483aff4f6a38f3945375d82..fb906cd4b6e0b140d7e5b7c46d60be707c9daf4d 100644
--- a/python/paddle/v2/dataset/movielens.py
+++ b/python/paddle/v2/dataset/movielens.py
@@ -23,7 +23,7 @@ set and test set into paddle reader creators.
 """
 
 import zipfile
-from common import download
+import paddle.v2.dataset.common
 import re
 import random
 import functools
@@ -99,7 +99,7 @@ USER_INFO = None
 
 
 def __initialize_meta_info__():
-    fn = download(URL, "movielens", MD5)
+    fn = paddle.v2.dataset.common.download(URL, "movielens", MD5)
     global MOVIE_INFO
     if MOVIE_INFO is None:
         pattern = re.compile(r'^(.*)\((\d+)\)$')
@@ -246,7 +246,15 @@ def unittest():
 
 
 def fetch():
-    download(URL, "movielens", MD5)
+    paddle.v2.dataset.common.download(URL, "movielens", MD5)
+
+
+def convert(path):
+    """
+    Converts dataset to recordio format
+    """
+    paddle.v2.dataset.common.convert(path, train(), 10, "movielens_train")
+    paddle.v2.dataset.common.convert(path, test(), 10, "movielens_test")
 
 
 if __name__ == '__main__':
diff --git a/python/paddle/v2/dataset/sentiment.py b/python/paddle/v2/dataset/sentiment.py
index 4dd34e7383fe2a290fcf61474914183a383e2b9c..89683c2063c68d13b2708fa91ab420fa9ff64e1a 100644
--- a/python/paddle/v2/dataset/sentiment.py
+++ b/python/paddle/v2/dataset/sentiment.py
@@ -26,7 +26,7 @@ from itertools import chain
 import nltk
 from nltk.corpus import movie_reviews
 
-import common
+import paddle.v2.dataset.common
 
 __all__ = ['train', 'test', 'get_word_dict']
 NUM_TRAINING_INSTANCES = 1600
@@ -39,12 +39,13 @@ def download_data_if_not_yet():
     """
     try:
         # make sure that nltk can find the data
-        if common.DATA_HOME not in nltk.data.path:
-            nltk.data.path.append(common.DATA_HOME)
+        if paddle.v2.dataset.common.DATA_HOME not in nltk.data.path:
+            nltk.data.path.append(paddle.v2.dataset.common.DATA_HOME)
         movie_reviews.categories()
     except LookupError:
         print "Downloading movie_reviews data set, please wait....."
-        nltk.download('movie_reviews', download_dir=common.DATA_HOME)
+        nltk.download(
+            'movie_reviews', download_dir=paddle.v2.dataset.common.DATA_HOME)
         print "Download data set success....."
         print "Path is " + nltk.data.find('corpora/movie_reviews').path
 
@@ -128,4 +129,13 @@ def test():
 
 
 def fetch():
-    nltk.download('movie_reviews', download_dir=common.DATA_HOME)
+    nltk.download(
+        'movie_reviews', download_dir=paddle.v2.dataset.common.DATA_HOME)
+
+
+def convert(path):
+    """
+    Converts dataset to recordio format
+    """
+    paddle.v2.dataset.common.convert(path, train, 10, "sentiment_train")
+    paddle.v2.dataset.common.convert(path, test, 10, "sentiment_test")
diff --git a/python/paddle/v2/dataset/uci_housing.py b/python/paddle/v2/dataset/uci_housing.py
index 3469fd9ce12dd4d934004f90286979b73048a5c8..9e15000c028efaf266921c94f2de4c397edb79c0 100644
--- a/python/paddle/v2/dataset/uci_housing.py
+++ b/python/paddle/v2/dataset/uci_housing.py
@@ -14,14 +14,14 @@
 """
 UCI Housing dataset.
 
-This module will download dataset from
+This module will paddle.v2.dataset.common.download dataset from
 https://archive.ics.uci.edu/ml/machine-learning-databases/housing/ and
 parse training set and test set into paddle reader creators.
 """
 
 import numpy as np
 import os
-from common import download
+import paddle.v2.dataset.common
 
 __all__ = ['train', 'test']
 
@@ -82,7 +82,7 @@ def train():
     :rtype: callable
     """
     global UCI_TRAIN_DATA
-    load_data(download(URL, 'uci_housing', MD5))
+    load_data(paddle.v2.dataset.common.download(URL, 'uci_housing', MD5))
 
     def reader():
         for d in UCI_TRAIN_DATA:
@@ -102,7 +102,7 @@ def test():
     :rtype: callable
     """
     global UCI_TEST_DATA
-    load_data(download(URL, 'uci_housing', MD5))
+    load_data(paddle.v2.dataset.common.download(URL, 'uci_housing', MD5))
 
     def reader():
         for d in UCI_TEST_DATA:
@@ -112,4 +112,12 @@ def test():
 
 
 def fetch():
-    download(URL, 'uci_housing', MD5)
+    paddle.v2.dataset.common.download(URL, 'uci_housing', MD5)
+
+
+def convert(path):
+    """
+    Converts dataset to recordio format
+    """
+    paddle.v2.dataset.common.convert(path, train(), 10, "uci_housing_train")
+    paddle.v2.dataset.common.convert(path, test(), 10, "uci_houseing_test")
diff --git a/python/paddle/v2/dataset/wmt14.py b/python/paddle/v2/dataset/wmt14.py
index 0902f87741c342b237439081703081b467dc6f35..f29c9275f049d52e46fc00d2374b35c26e953ba4 100644
--- a/python/paddle/v2/dataset/wmt14.py
+++ b/python/paddle/v2/dataset/wmt14.py
@@ -22,7 +22,7 @@ parse training set and test set into paddle reader creators.
 import tarfile
 import gzip
 
-from paddle.v2.dataset.common import download
+import paddle.v2.dataset.common
 from paddle.v2.parameters import Parameters
 
 __all__ = ['train', 'test', 'build_dict']
@@ -115,7 +115,8 @@ def train(dict_size):
     :rtype: callable
     """
     return reader_creator(
-        download(URL_TRAIN, 'wmt14', MD5_TRAIN), 'train/train', dict_size)
+        paddle.v2.dataset.common.download(URL_TRAIN, 'wmt14', MD5_TRAIN),
+        'train/train', dict_size)
 
 
 def test(dict_size):
@@ -130,16 +131,18 @@ def test(dict_size):
     :rtype: callable
     """
     return reader_creator(
-        download(URL_TRAIN, 'wmt14', MD5_TRAIN), 'test/test', dict_size)
+        paddle.v2.dataset.common.download(URL_TRAIN, 'wmt14', MD5_TRAIN),
+        'test/test', dict_size)
 
 
 def gen(dict_size):
     return reader_creator(
-        download(URL_TRAIN, 'wmt14', MD5_TRAIN), 'gen/gen', dict_size)
+        paddle.v2.dataset.common.download(URL_TRAIN, 'wmt14', MD5_TRAIN),
+        'gen/gen', dict_size)
 
 
 def model():
-    tar_file = download(URL_MODEL, 'wmt14', MD5_MODEL)
+    tar_file = paddle.v2.dataset.common.download(URL_MODEL, 'wmt14', MD5_MODEL)
     with gzip.open(tar_file, 'r') as f:
         parameters = Parameters.from_tar(f)
     return parameters
@@ -148,7 +151,7 @@ def model():
 def get_dict(dict_size, reverse=True):
     # if reverse = False, return dict = {'a':'001', 'b':'002', ...}
     # else reverse = true, return dict = {'001':'a', '002':'b', ...}
-    tar_file = download(URL_TRAIN, 'wmt14', MD5_TRAIN)
+    tar_file = paddle.v2.dataset.common.download(URL_TRAIN, 'wmt14', MD5_TRAIN)
     src_dict, trg_dict = __read_to_dict__(tar_file, dict_size)
     if reverse:
         src_dict = {v: k for k, v in src_dict.items()}
@@ -157,5 +160,14 @@ def get_dict(dict_size, reverse=True):
 
 
 def fetch():
-    download(URL_TRAIN, 'wmt14', MD5_TRAIN)
-    download(URL_MODEL, 'wmt14', MD5_MODEL)
+    paddle.v2.dataset.common.download(URL_TRAIN, 'wmt14', MD5_TRAIN)
+    paddle.v2.dataset.common.download(URL_MODEL, 'wmt14', MD5_MODEL)
+
+
+def convert(path):
+    """
+    Converts dataset to recordio format
+    """
+    dict_size = 30000
+    paddle.v2.dataset.common.convert(path, train(dict_size), 10, "wmt14_train")
+    paddle.v2.dataset.common.convert(path, test(dict_size), 10, "wmt14_test")