OBJECTIVE:To evaluate the clinical efficacy of safflower yellow injection combined with conventional therapy in treating unstable angina pectoris.METHODS:We searched online databases:Chinese journal full-text database,China National Knowledge Infrastructure,Wanfang database,Chinese journal full-text database,Pubmed,ScienceDirect,Embase,and the Cochrane Library with manual-screening of relevant literature.Eligible randomized controlled trials(RCT)on angina pectoris were included.We conducted meta-analysis using the RevMan 5.1 software from The Cochrane Collaboration.We treated the relief rate of angina symptoms and electrocardiograph(ECG)as evaluation.RESULTS:Seven articles,including in 1134 patients,were enrolled after the evaluation.Therewas no significant heterogeneity among the studies(χ2=1.08,df=6,P=0.98,I2=0%).The safflower yellow injection with conventional therapy has a higher effective rate than the control group in relieving the symptoms of angina pectoris[odds ratio(OR)=2.95,95%(CI)(1.81,4.81)]and improving ischemic ECG[OR=2.85,95%CI(1.67,4.86)].The difference was statistically significant in the"80 mg dosage"and"100 mg dosage"subgroups(P