Objective To evaluate the effect of Guantong Formula（Formula for the stenosis of coronary artery）on the restenosis after intracoronary bare stenting.Methods Totally 120 patients after successful intracoronary bare stenting were randomized into control group and treatment group.The control group was treated with routine medicines

based on which the treatment group was administered Guantong Formula.The treatment course was 6 months.Quantitative coronary analysis was made for all patients with the angiograms of pre-intervention

post-intervention and follow-up for comparing the incidence of restenosis and diameter of involved blood vessel of both groups.Results The coronary angiographic examination showed that the restenosis rate of the control group was 23.73% while that of the treatment group was 9.84%

the difference was significant（P<0.05）.After treatment

in the late stage

the loss of diameter in the treatment group was smaller than that of the control group（P<0.05）

the minimum diameter

the net gain of luminal diameter

and the net gain of luminal area were all larger than those of the control group（P<0.05 or P<0.01）.Conclusion Guantong Formula is effective in preventing restenosis after intracoronary bare stenting.