diff --git a/data_juicer/ops/mapper/nlpaug_en_mapper.py b/data_juicer/ops/mapper/nlpaug_en_mapper.py
index 6a5148c7b..8509c1ba0 100644
--- a/data_juicer/ops/mapper/nlpaug_en_mapper.py
+++ b/data_juicer/ops/mapper/nlpaug_en_mapper.py
@@ -125,7 +125,7 @@ def process(self, samples):
                 if key == self.text_key:
                     res_samples[self.text_key] += aug_texts
                 else:
-                    res_samples[key] += res_samples[key] * self.aug_num
+                    res_samples[key] += res_samples[key] * len(aug_texts)
         else:
             # apply each aug method to generate several augmented texts
             for aug_method in self.aug:
@@ -134,6 +134,6 @@ def process(self, samples):
             # add other replicate fields
             for key in res_samples:
                 if key != self.text_key:
-                    res_samples[key] += res_samples[key] * self.aug_num \
-                                        * len(self.aug)
+                    res_samples[key] = res_samples[key] * \
+                                       len(res_samples[self.text_key])
         return res_samples