Abstract: OBJECTIVE To observe the effect of Yiqi Huoxue Huayu recipe on coronary blood flow and main clinical symptoms in patients with slow blood flow after percutaneous coronary intervention (PCI). METHODS 44 patients were randomly divided into treatment group and control group， 22 cases in each group. All patients received daily secondary prevention drugs for coronary heart disease (double antiplatelet drugs， statins， ACEI/ARB drugs and beta blockers) from 24 hours after surgery. On the basis of this treatment， The treatment group was given Yiqi Huoxue Huatan recipe， one dose a day. After 3 months of treatment， the changes of coronary blood flow (TIMI blood flow grading and corrected TIMI frame) before and after treatment， TCM syndrome scores and main clinical symptoms (number of angina pectoris， duration， nitroglycerin dosage) were observed. RESULTS The TIMI blood flow grading and corrected TIMI frame number in the treatment group were significantly changed (P<0.05， P<0.01). The TCM syndrome scores in the treatment group were significantly lower before and after treatment (P<0.05， P<0.01). The main clinical symptoms were significantly improved (P<0.01)， the degree of improvement was significantly better than the control group (P<0.01). CONCLUSION Yiqi Huoxue Huatan recipe can improve coronary blood flow and main clinical symptoms in patients with slow blood flow after PCI.