OBJECTIVE： To systematically evaluate the efficacy and safety of ticagrelor versus clopidogrel in the treatment of acute coronary syndrome （ACS）. METHODS： Retrieved from PubMed， Embase， Cochrane Library， CBM and CNKI， randomized controlled trials （RCTs） about ticagrelor （trial group） and clopidogrel （control group） in the treatment of ACS were included. After literature screening， data extraction and quality evaluation with modified Jadad scale， Meta-analysis was performed by using Rev Man 5.3 software. RESULTS： 26 RCTs were included， involving 8 560 patients. Meta-analysis showed that the incidence of main adverse cardiac event [RR＝0.47，95％CI（0.38，0.57），P＜0.000 01] and stroke [RR＝0.24，95％CI（0.08，0.69），P＝0.008]， platelet aggregation rate [SMD＝－3.16，95％CI（－4.16，－2.16），P＜0.000 01] and C-reactive protein level [SMD＝－1.02，95％CI（－1.76，－0.29），P＝0.006] in trial group were significantly lower than control group； uric acid level [SMD＝0.64，95％CI（0.39，0.88），P＜0.000 01] of trial group was significantly higher than control group. There was no statistical significance in the incidence of main bleeding event [RR＝0.96，95％CI（0.66，1.40），P＝0.85] or dyspnea [RR＝1.19，95％CI（0.78，1.80），P＝0.42] between 2 groups. CONCLUSIONS： The efficacy and safety of ticagrelor is superior to those of clopidogrel in treatment of ACS， but ticagrelor can cause the elevation of uric acid.