Abstract： Objective： To observe the clinical effect of Xihuang Capsules combined with Trastuzumab for epidermal growth factor receptor 2 (Her- 2)- positive advanced breast cancer and its effects on carcinoembryonic antigen (CEA) and carbohydrate antigen 153 (CA153) in serum. Methods ： A total of 86 cases of patients with Her-2-positive advanced breast cancer were selected as the study objects，and divided into the observation group and the control group according to the random number table method， with 43 cases in each group. The control group was treated with Trastuzumab，and the observation group was treated with Xihuang Capsules combined with Trastuzumab. Clinical effects and the incidence of adverse reactions were compared between the two groups. The changes in traditional Chinese medicine (TCM) syndrome scores，the levels of CEA and CA153 in serum，and the immune function before and after treatment were compared between the two groups. Results：After treatment，the TCM syndrome scores including emotional depression (or irritability)， chest oppression and rib- side distension， tidal fever and profuse sweating，pale complexion，and thin coating in the two groups were decreased when compared with those before treatment (P＜0.05)， and the above 5 TCM syndrome scores in the observation group were lower than those in the control group (P＜0.05). After treatment， the total effective rate of clinical effect was 76.74% in the observation group and 51.16% in the control group， the difference being significant (P＜0.05). After treatment， the levels of CEA and CA153 in serum in the two groups were decreased when compared with those before treatment (P＜0.05)，and the levels in the observation group were lower than those in the control group (P＜0.05). After treatment，the index values of immunoglobulin (Ig)A，IgM，CD4 +，and CD4 +/CD8 + in the two groups were increased when compared with those before treatment， and the index values of CD8 + were decreased when compared with those before treatment； the index values of IgA，IgM，CD4+，and CD4+/CD8+ in the observation group were higher than those in the control group， and the index value of CD8 + was lower than that in the control group； differences were significant (P＜0.05). The incidence of adverse reactions including dizziness and headache，digestive tract symptoms， cardiotoxicity， liver and kidney damage， and bone marrow depression in the observation group was lower than that in the control group， differences being significant (P＜0.05). Conclusion： Xihuang Capsules combined with Trastuzumab for Her-2-positive advanced breast cancer can improve the clinical effect，the immune function of body and prognosis，with high medication safety.