diff --git a/python/paddle/v2/dataset/cifar.py b/python/paddle/v2/dataset/cifar.py
index d9f7a830ee60a331b55a1e218923e690103e1c5b..3a8b98b8f045b0eb58be69649486cbd0a571f118 100644
--- a/python/paddle/v2/dataset/cifar.py
+++ b/python/paddle/v2/dataset/cifar.py
@@ -20,7 +20,7 @@ TODO(yuyang18): Complete the comments.
 import cPickle
 import itertools
 import numpy
-import paddle.v2.dataset.common
+from common import download
 import tarfile
 
 __all__ = ['train100', 'test100', 'train10', 'test10']
@@ -55,23 +55,23 @@ def reader_creator(filename, sub_name):
 
 def train100():
     return reader_creator(
-        paddle.v2.dataset.common.download(CIFAR100_URL, 'cifar', CIFAR100_MD5),
-        'train')
+        download(CIFAR100_URL, 'cifar', CIFAR100_MD5), 'train')
 
 
 def test100():
-    return reader_creator(
-        paddle.v2.dataset.common.download(CIFAR100_URL, 'cifar', CIFAR100_MD5),
-        'test')
+    return reader_creator(download(CIFAR100_URL, 'cifar', CIFAR100_MD5), 'test')
 
 
 def train10():
     return reader_creator(
-        paddle.v2.dataset.common.download(CIFAR10_URL, 'cifar', CIFAR10_MD5),
-        'data_batch')
+        download(CIFAR10_URL, 'cifar', CIFAR10_MD5), 'data_batch')
 
 
 def test10():
     return reader_creator(
-        paddle.v2.dataset.common.download(CIFAR10_URL, 'cifar', CIFAR10_MD5),
-        'test_batch')
+        download(CIFAR10_URL, 'cifar', CIFAR10_MD5), 'test_batch')
+
+
+def fetch():
+    download(CIFAR10_URL, 'cifar', CIFAR10_MD5)
+    download(CIFAR100_URL, 'cifar', CIFAR100_MD5)
diff --git a/python/paddle/v2/dataset/common.py b/python/paddle/v2/dataset/common.py
index 3021b68ddb02ecaa874e21681796c0912ad4cc06..7021a6da05dec6be216534112c2df2586e73390f 100644
--- a/python/paddle/v2/dataset/common.py
+++ b/python/paddle/v2/dataset/common.py
@@ -17,6 +17,8 @@ import hashlib
 import os
 import shutil
 import sys
+import importlib
+import paddle.v2.dataset
 
 __all__ = ['DATA_HOME', 'download', 'md5file']
 
@@ -69,3 +71,13 @@ def dict_add(a_dict, ele):
         a_dict[ele] += 1
     else:
         a_dict[ele] = 1
+
+
+def fetch_all():
+    for module_name in filter(lambda x: not x.startswith("__"),
+                              dir(paddle.v2.dataset)):
+        if "fetch" in dir(
+                importlib.import_module("paddle.v2.dataset.%s" % module_name)):
+            getattr(
+                importlib.import_module("paddle.v2.dataset.%s" % module_name),
+                "fetch")()
diff --git a/python/paddle/v2/dataset/conll05.py b/python/paddle/v2/dataset/conll05.py
index 9eab49ee39325c1c60fc511e0bd834e83aa987f0..f1b0ce16f21ad13d4564242c2359355236093032 100644
--- a/python/paddle/v2/dataset/conll05.py
+++ b/python/paddle/v2/dataset/conll05.py
@@ -196,3 +196,11 @@ def test():
         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)
diff --git a/python/paddle/v2/dataset/imdb.py b/python/paddle/v2/dataset/imdb.py
index 76019d9f54020ff6f02c17eb6047cbd014a8ccf2..5284017ce08de8beb559f58fb6006639f40f5580 100644
--- a/python/paddle/v2/dataset/imdb.py
+++ b/python/paddle/v2/dataset/imdb.py
@@ -123,3 +123,7 @@ def test(word_idx):
 def word_dict():
     return build_dict(
         re.compile("aclImdb/((train)|(test))/((pos)|(neg))/.*\.txt$"), 150)
+
+
+def fetch():
+    paddle.v2.dataset.common.download(URL, 'imdb', MD5)
diff --git a/python/paddle/v2/dataset/imikolov.py b/python/paddle/v2/dataset/imikolov.py
index 97c160f111d09d61eb860c7f02552e635f2400a7..2931d06e7eb65bde887c56a8bc20e7a9c5e4d4e4 100644
--- a/python/paddle/v2/dataset/imikolov.py
+++ b/python/paddle/v2/dataset/imikolov.py
@@ -89,3 +89,7 @@ def train(word_idx, n):
 
 def test(word_idx, n):
     return reader_creator('./simple-examples/data/ptb.valid.txt', word_idx, n)
+
+
+def fetch():
+    paddle.v2.dataset.common.download(URL, "imikolov", MD5)
diff --git a/python/paddle/v2/dataset/mnist.py b/python/paddle/v2/dataset/mnist.py
index 16f2fcb99de4cb1971a7375a97b5daa209ee95ef..48a39b5493a8004d6eb034498a797af9c662bd19 100644
--- a/python/paddle/v2/dataset/mnist.py
+++ b/python/paddle/v2/dataset/mnist.py
@@ -106,3 +106,10 @@ def test():
                                           TEST_IMAGE_MD5),
         paddle.v2.dataset.common.download(TEST_LABEL_URL, 'mnist',
                                           TEST_LABEL_MD5), 100)
+
+
+def fetch():
+    paddle.v2.dataset.common.download(TRAIN_IMAGE_URL, 'mnist', TRAIN_IMAGE_MD5)
+    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)
diff --git a/python/paddle/v2/dataset/movielens.py b/python/paddle/v2/dataset/movielens.py
index 25fd8227da2f219d75c6b830e65627ecf35be453..e148ddeca0370cd76128a31ce3a4d488e9737d98 100644
--- a/python/paddle/v2/dataset/movielens.py
+++ b/python/paddle/v2/dataset/movielens.py
@@ -30,6 +30,9 @@ __all__ = [
 
 age_table = [1, 18, 25, 35, 45, 50, 56]
 
+URL = 'http://files.grouplens.org/datasets/movielens/ml-1m.zip'
+MD5 = 'c4d9eecfca2ab87c1945afe126590906'
+
 
 class MovieInfo(object):
     def __init__(self, index, categories, title):
@@ -77,10 +80,7 @@ USER_INFO = None
 
 
 def __initialize_meta_info__():
-    fn = download(
-        url='http://files.grouplens.org/datasets/movielens/ml-1m.zip',
-        module_name='movielens',
-        md5sum='c4d9eecfca2ab87c1945afe126590906')
+    fn = download(URL, "movielens", MD5)
     global MOVIE_INFO
     if MOVIE_INFO is None:
         pattern = re.compile(r'^(.*)\((\d+)\)$')
@@ -205,5 +205,9 @@ def unittest():
     print train_count, test_count
 
 
+def fetch():
+    download(URL, "movielens", MD5)
+
+
 if __name__ == '__main__':
     unittest()
diff --git a/python/paddle/v2/dataset/sentiment.py b/python/paddle/v2/dataset/sentiment.py
index 71689fd61b6b14a7b5072caff4e2fd48a7f74072..0eeb6d5affd8c280fb74edc82cf24bf418ca8ef9 100644
--- a/python/paddle/v2/dataset/sentiment.py
+++ b/python/paddle/v2/dataset/sentiment.py
@@ -125,3 +125,7 @@ def test():
     """
     data_set = load_sentiment_data()
     return reader_creator(data_set[NUM_TRAINING_INSTANCES:])
+
+
+def fetch():
+    nltk.download('movie_reviews', download_dir=common.DATA_HOME)
diff --git a/python/paddle/v2/dataset/uci_housing.py b/python/paddle/v2/dataset/uci_housing.py
index 27f454b137e3a40febd19cf085e2f4034cc16b24..dab8620441c966b19d8218025f8d8fa5b40d1c2c 100644
--- a/python/paddle/v2/dataset/uci_housing.py
+++ b/python/paddle/v2/dataset/uci_housing.py
@@ -89,3 +89,7 @@ def test():
             yield d[:-1], d[-1:]
 
     return reader
+
+
+def fetch():
+    download(URL, 'uci_housing', MD5)
diff --git a/python/paddle/v2/dataset/wmt14.py b/python/paddle/v2/dataset/wmt14.py
index c686870a497668517d1c78c11c616ad8a71a2980..ee63a93f5ad918b5bbc949ae6ba29082b3f6abd5 100644
--- a/python/paddle/v2/dataset/wmt14.py
+++ b/python/paddle/v2/dataset/wmt14.py
@@ -16,7 +16,7 @@ wmt14 dataset
 """
 import tarfile
 
-import paddle.v2.dataset.common
+from paddle.v2.dataset.common import download
 
 __all__ = ['train', 'test', 'build_dict']
 
@@ -95,11 +95,13 @@ def reader_creator(tar_file, file_name, dict_size):
 
 def train(dict_size):
     return reader_creator(
-        paddle.v2.dataset.common.download(URL_TRAIN, 'wmt14', MD5_TRAIN),
-        'train/train', dict_size)
+        download(URL_TRAIN, 'wmt14', MD5_TRAIN), 'train/train', dict_size)
 
 
 def test(dict_size):
     return reader_creator(
-        paddle.v2.dataset.common.download(URL_TRAIN, 'wmt14', MD5_TRAIN),
-        'test/test', dict_size)
+        download(URL_TRAIN, 'wmt14', MD5_TRAIN), 'test/test', dict_size)
+
+
+def fetch():
+    download(URL_TRAIN, 'wmt14', MD5_TRAIN)