Abstract：Objectives：To observe the effect of Fuzheng Xiaoliu granules on human epidermal growth factor receptor 2 (HER- 2) mRNA and protein expressions in SKBR- 3 cells of breast cancer. Methods： A total of 30 SD rats were randomly divided into the Fuzheng Xiaoliu granules low- dose group(Group L)， median- dose group(Group M) and high- dose group (Group H). In the three groups，rats with medicated serum containing Fuzheng Xiaoliu granules were prepared by Fuzheng Xiaoliu granules by gavage at the doses of one， two and three times respectively. HER- 2- positive human breast cancer SKBR-3 cells were cultured in vitro. Rats with cells in the logarithmic growth phase were randomly divided into five groups， with the blank control group， the Herceptin group and the three groups of rats with medicated serum containing Fuzheng Xiaoliu granules at three different doses，and were given corresponding intervention. The HER- 2 mRNA expressions were detected by real-time polymerase chain reaction(PCR)，and the HER-2 protein expressions by Western Blot. Results：The HER-2 mRNA contents in the three groups of Fuzheng Xiaoliu granules and the Herceptin group were decreased at 24 h， 48 h and 72 h when compared with those in the blank control group(P＜0.01)，suggesting that rats with medicated serum at three doses and Herceptin could inhibit the HER- 2 mRNA expressions in SKBR- 3 cells. There was no significant difference being found in the comparison of HER-2 mRNA contents at 24 h and 48 h between Group L and the Herceptin group，and of HER- 2 mRNA contents at 48 h between Group M and the Herceptin group(P＞0.05). The comparisons between HER- 2 mRNA expressions in Group L at 72 h， Group M at 24 h and 72 h， Group H at 24 h， 48 h and 72 h and those in the Herceptin group showed significant differences(P＜0.01，P＜0.05). The HER-2 mRNA contents at 24h in the three groups of Fuzheng Xiaoliu granules at three doses and the Herceptin group were the lowest，the HER-2 mRNA contents at 48 h were increased when compared with those at 24 h，and decreased at 72 h. The HER- 2 protein contents of SKBR- 3 cells in the Herceptin group and Group L were decreased when compared with those in the blank control group， differences being significant(P＜0.01). The HER- 2 protein contents in Group M and Group H were higher than those in the Herceptin group， differences being significant(P＜0.01). There was no significant difference being found in the comparison of HER- 2 protein content between the Herceptin group and Group L(P＞0.05). Conclusion：The medicated serum containing Fuzheng Xiaoliu granules can obviously inhibit the HER-2 mRNA and protein expressions in SKBR-3 cells of breast cancer，whose inhibitory effect is worse than that of Herceptin，and the medicated serum with low-dose Fuzheng Xiaoliu granules has better effect.