diff --git a/BERT/reader/pretraining.py b/BERT/reader/pretraining.py
index 182e627ab2b1056031d13c29df2ad0cce413020b..35a3720eaf8d383e19584ed114322685c517ce3a 100644
--- a/BERT/reader/pretraining.py
+++ b/BERT/reader/pretraining.py
@@ -36,6 +36,7 @@ class DataReader(object):
                  data_dir,
                  vocab_path,
                  batch_size=4096,
+                 in_tokens=True,
                  max_seq_len=512,
                  shuffle_files=True,
                  epoch=100,
@@ -46,6 +47,7 @@ class DataReader(object):
         self.vocab = self.load_vocab(vocab_path)
         self.data_dir = data_dir
         self.batch_size = batch_size
+        self.in_tokens = in_tokens
         self.shuffle_files = shuffle_files
         self.epoch = epoch
         self.current_epoch = 0
@@ -60,8 +62,9 @@ class DataReader(object):
         self.mask_id = self.vocab["[MASK]"]
         self.is_test = is_test
         self.generate_neg_sample = generate_neg_sample
-        assert self.batch_size > 100, "Current batch size means total token's number, \
-                                       it should not be set to too small number."
+        if self.in_tokens:
+            assert self.batch_size >= self.max_seq_len, "The number of " \
+                   "tokens in batch should not be smaller than max seq length."
 
         if self.is_test:
             self.epoch = 1
@@ -245,12 +248,16 @@ class DataReader(object):
                                 continue
                             yield sample
 
-            def batch_reader(reader, batch_size):
+            def batch_reader(reader, batch_size, in_tokens):
                 batch, total_token_num, max_len = [], 0, 0
                 for parsed_line in reader():
                     token_ids, sent_ids, pos_ids, label = parsed_line
                     max_len = max(max_len, len(token_ids))
-                    if (len(batch) + 1) * max_len <= batch_size:
+                    if in_tokens:
+                        to_append = (len(batch) + 1) * max_len <= batch_size
+                    else:
+                        to_append = len(batch) < batch_size
+                    if to_append:
                         batch.append(parsed_line)
                         total_token_num += len(token_ids)
                     else:
@@ -261,8 +268,8 @@ class DataReader(object):
                 if len(batch) > 0:
                     yield batch, total_token_num
 
-            for batch_data, total_token_num in batch_reader(reader,
-                                                            self.batch_size):
+            for batch_data, total_token_num in batch_reader(
+                    reader, self.batch_size, self.in_tokens):
                 yield prepare_batch_data(
                     batch_data,
                     total_token_num,
diff --git a/BERT/train.py b/BERT/train.py
index 51df8705d9adcd18f1a8ae0f9674158e776bd49e..64c751c44735fdc90e9bd284b356cde3467e13f7 100644
--- a/BERT/train.py
+++ b/BERT/train.py
@@ -61,14 +61,15 @@ log_g.add_arg("verbose",             bool,   False, "Whether to output verbose l
 
 data_g = ArgumentGroup(parser, "data", "Data paths, vocab paths and data processing options")
 data_g.add_arg("data_dir",            str,  "./data/train/",       "Path to training data.")
-data_g.add_arg("validation_set_dir",  str,  "./data/validation/",  "Path to training data.")
-data_g.add_arg("test_set_dir",        str,  None,                  "Path to training data.")
+data_g.add_arg("validation_set_dir",  str,  "./data/validation/",  "Path to validation data.")
+data_g.add_arg("test_set_dir",        str,  None,                  "Path to test data.")
 data_g.add_arg("vocab_path",          str,  "./config/vocab.txt",  "Vocabulary path.")
-data_g.add_arg("max_seq_len",         int,  512,                   "Number of words of the longest seqence.")
-data_g.add_arg("batch_size",          int,  16,                    "Total examples' number in batch for training. see also --in_tokens.")
-data_g.add_arg("in_tokens",           bool, False,
-              "If set, the batch size will be the maximum number of tokens in one batch. "
-              "Otherwise, it will be the maximum number of examples in one batch.")
+data_g.add_arg("max_seq_len",         int,  512,                   "Tokens' number of the longest seqence allowed.")
+data_g.add_arg("batch_size",          int,  8192,
+               "The total number of examples in one batch for training, see also --in_tokens.")
+data_g.add_arg("in_tokens",           bool, True,
+               "If set, the batch size will be the maximum number of tokens in one batch. "
+               "Otherwise, it will be the maximum number of examples in one batch.")
 
 run_type_g = ArgumentGroup(parser, "run_type", "running type options.")
 run_type_g.add_arg("is_distributed",    bool,   False,  "If set, then start distributed training.")
@@ -128,6 +129,7 @@ def predict_wrapper(args,
         data_path,
         vocab_path=args.vocab_path,
         batch_size=args.batch_size,
+        in_tokens=args.in_tokens,
         voc_size=bert_config['vocab_size'],
         shuffle_files=False,
         epoch=1,
@@ -250,9 +252,16 @@ def train(args):
         dev_count = int(os.environ.get('CPU_NUM', multiprocessing.cpu_count()))
 
     print("Device count %d" % dev_count)
-    print("theoretical memory usage: ")
-    print(fluid.contrib.memory_usage(
-        program=train_program, batch_size=args.batch_size // args.max_seq_len))
+    if args.verbose:
+        if args.in_tokens:
+            lower_mem, upper_mem, unit = fluid.contrib.memory_usage(
+         program=train_program,
+         batch_size=args.batch_size // args.max_seq_len)
+        else:
+            lower_mem, upper_mem, unit = fluid.contrib.memory_usage(
+         program=train_program, batch_size=args.batch_size)
+        print("Theoretical memory usage in training: %.3f - %.3f %s" %
+              (lower_mem, upper_mem, unit))
 
     nccl2_num_trainers = 1
     nccl2_trainer_id = 0
@@ -293,6 +302,7 @@ def train(args):
     data_reader = DataReader(
         data_dir=args.data_dir,
         batch_size=args.batch_size,
+        in_tokens=args.in_tokens,
         vocab_path=args.vocab_path,
         voc_size=bert_config['vocab_size'],
         epoch=args.epoch,