Abstract： Objective To explore the clinical effect of trastuzumab combination chemotherapy in the treatment of human epidermal growth factor receptor-2(HER-2)-positive breast cancer.Methods 73 cases of HER-2 positive breast cancer patients were selected and divided into two groups according to the admission time.36 cases in the control group were treated with trastuzumab and 37 cases in the observation group were treated with trastuzumab combined with chemotherapy.The tumor control effect,tumor markers,immune markers,hormone markers,nucleus-related antigen(Ki67)expression and the occurrence of adverse reactions were compared between the two groups.Results The comparison of efficacy between the two groups was with P<0.05.After intervention,the levels of carcinoembryonic antigen(CEA),nucleus-associated antigen(Ki67),sugar antigen 125(CA-125),CD8+,CD4+/CD8+all decreased,and those in the observation group were lower than those in the control group(P<0.05).After intervention,the levels of CD3+,CD4+,estrogen receptor(ER)and progesterone receptor(PR)all increased in the two groups,and those in the observation group were higher than those in the control group(P<0.05).There was no significant difference in the incidence of adverse reaction between the two groups(P>0.05).Conclusion Trastuzumab combined with chemotherapy for HER-2 positive breast cancer can reduce the levels of tumor markers,improve the immune index,alleviate the levels of Ki67,PR and ER.