Objective:To observe the clinical efficacy of Gualou Xiebai Granule in the prevention and treatment of percutaneous coronary intervention(PCI)postoperative restenosis in soft plaque of coronary artery with syndrome of phlegm-dampness blocking. Methods100 patients with soft plaque of coronary artery of phlegm-dampness blocking syndrome who had received PCI operation were randomly divided into the treatment group and control group,50 cases in each group. The control group was treated with the routine therapy of western medicine,and the treatment group was treated with Gualou Xiebai Granule based on the treatment for the control group,with a course of one years. The PCI postoperative restenosis of coronary artery was observed,and the blood lipid metabolism related indexes(including total cholesterol ,triglyceride ,low density lipoprotein and high density lipoprotein )and Chinese medical syndrome score were compared before and after treatment.  Results:①During the trial,5 cases in the treatment group and 5 cases in the control group fell off,and finally 90 cases completed the trial. ②The incidence rates of PCI postoperative restenosis of coronary artery were 2.22% in the treatment group and 20.00% in the control group. There was statistically significant difference on the incidence rate of PCI postoperative restenosis of coronary artery between the two groups,and the incidence rate of the treatment group was obviously lower than that of the control group(P<0.05). ③After treatment,there were statistically significant differences on the levels of TC,TG,LDL-C and HDL-C between the two groups,and the levels of TC,TG and LDL-C in the treatment group were obviously lower than those in the control group,the HDL-C level in the treatment group was obviously higher than that in the control group(P<0.05). ④After treatment,the Chinese medical syndrome score of the treatment group was obviously lower than that of the control group(P<0.05).  Conclusion:Gualou Xiebai Granule combined with conventional western medicine can obviously decrease the incidence rate of PCI postoperative restenosis in soft plaque of coronary artery with syndrome of phlegm-dampness blocking,reduce the levels of blood lipid and improve the clinical symptoms.