OBJECTIVE To evaluate the effectiveness and safety of trastuzumab biosimilars and original drugs in the treatment of human epidermal growth factor receptor -2（HER-2）positive breast cancer systematically ，and to provide evidence -based basis for the selection of clinical treatment . METHODS Retrieved from PubMed ，Embase，Web of Science ，Cochrane Library ，CNKI， CBM，VIP，Wanfang database ，ClinicalTrials and Clinical Trial Center of China ，randomized controlled trials （RCTs）about trastuzumab biosimilars （trial group ）versus original drugs （control group ）in the treatment of HER -2 positive breast cancer were collected. After data extraction and quality evaluation ，RevMan 5.4 statistical software was used for meta -analysis. RESULTS Totally 11 RCTs were enrolled ，involving 5 812 patients. Results of meta -analysis showed that there was no significant difference in objective response rate （based on whether intention -to-treat population nor per -protocol population ），pathologic complete response ， proportion of progression free survival population ，proportion of overall survival population ，anti-drug antibody positive rate ， neutralizing antibody positive rate ，and incidence of adverse drug reactions between 2 groups（P＞0.05）. CONCLUSIONS The effectiveness and safety of trastuzumab biosimilars are equivalent to those of trastuzumab original drugs .