Objective To systematically review the effectiveness and safety of safflor yellow for unstable angina. Methods Relevant studies of safflor yellow for unstable angina were collected from databases including CENTRAL (Issue 4, 2012), MEDLINE, EMbase, CNKI, VIP, WanFang Data and CBM from January, 2007 to December, 2012. Two reviewers independently screened literature according to the inclusion and exclusion criteria, extracted data and assessed the quality of the included studies. Then, meta-analysis was performed using RevMan 5.1 software. Results A total of 6 RCTs involving 533 patients were included, which were of low quality. The results of meta-analysis showed: compared with conventional treatment alone, safflor yellow plus routine biomedical treatment significantly improved the symptoms f angina (excellence: OR=2.34, 95%CI 1.79 to 4.87; effectiveness: OR=1.23, 95%CI 0.86 to 1.76). Besides, it significantly improved ECG outcomes (excellence: OR=1.85, 95%CI 1.29 to 2.64; effectiveness: OR=1.43, 95%CI 1.00 to 2.05), obviously improved the hemorheology index and blood lipid, reduced plasma homocysteine concentration, and increased the decreasing of nitroglycerin stop amount. No damage of the liver and kidney were reported. Conclusion Current evidence showed that, safflor yellow plus routine biomedical treatment is effective in the treatment of unstable angina, which is superior to routine biomedical treatment alone. Due to the limited quantity and quality of the included studies, more high quality, double blind, randomized controlled trials are needed to verify the above conclusion.