Objective:To systematically evaluate the effectiveness and safety of Sodium Tanshinone Ⅱ A Sulfonate Injection (STS) as one adjuvant therapy for treating unstable angina pectoris (UAP).Methods:Randomized controlled trials (RCTs) of UAP treated by STS were searched in the China National Knowledge Infrastructure Database (CNKI),VIP Database for Chinese Technical Periodicals (VIP),Wanfang Database,the Chinese Biomedical Literature Database (CBM),Web of Science,the Cochrane Library,Embase,and PubMed,which from inception to January,2016.The Cochrane Risk Assessment Tool was used to evaluate the methodological quality of the RCTs.The Review Manager 5.3 software was used to conduct the metaanalysis.Results:The results showed that 17 RCTs involving 1,372 patients were included.The meta-analysis indicated that the combined use of STS and Western medicine (WM) in the treatment of UAP can obviously improve the total effective rate [risk ratio (RR)=1.31,95％ confidence interval (CI) (1.24,1.39),P＜0.0001],and the total effective rate of electrocardiogram [RR=1.43,95％ CI (1.30,1.56),P＜0.0001],decrease the level of CRP [mean difference (MD)---3.06,95％CI (-3.85,-2.27),P＜0.00001],fibrinogen [MD=-1.03,95％ CI (-1.16,-0.89),P＜0.00001],and whole blood high shear viscosity [MD=-0.70,95％ CI (-0.92,-0.49),P＜0.00001].Additionally,the occurrence of adverse drug reaction of the experimental group was significantly higher than that of the control group [RR=3.57,95％ CI (1.28,9.94),P＜0.05].Conclusions:Compared with WM,the combined use of STS was more effective.