Objective：To study the anticoagulant efficacy and safety of bivalirudin in treatment of aged（＞60 years） patients with acute coronary syndrome（ACS） and 3rd stage of chronic kidney disease（CKD3） undergoing percutaneous coronary intervention（PCI）. Methods：Totally 72 aged patients（＞70 years） with ACS and CKD3 who received PCI from March 2015 to May 2017 in the People’s Hospital of Jiaozuo City were randomly divided into bivalirudin group（37 cases） and unfractionated heparin（UFH） group（35 cases）. Bivalirudin group were treated with bivalirudin，while UFH group were treated with UFH in PCI. The changes of ACT value in the using medication process，renal function index（glomerular filtration rate，Scr，BUN） before and after using medication，major adverse cardio and cerebral vessels events（MACCE） within 30 days after operation，bleeding events within 7 d after surgery were monitored in two groups. Results：After treatment，the ACT values of two groups increased rapidly；the difference was not statistically significant in the ACT values on 5 min and 30 min after using drugs and immediate withdrawal（F=0.543，1.364，1.866；P=0.464，0.247，0.176）；the difference was not statistically significant in the standard-reaching rate of ACT values on 5 min and 30 min after using drugs and immediate withdrawal（P=0.233，0.219，0.233）；at 1，3，6 h after stopping the drug，the ACT value in the bivalirudin group was less than that in UFH group（F=110.084，79.462，7.572，all P=0.000）. The extubation time in the bivalirudin group was shorter than that in UFH group（t=-8.787，P=0.000）. The difference was not statistically significant between before and 24 h after administration in eGFR，Scr and BUN within the same group（all P>0.05），there was no statistical difference between two groups before and 24 h after administration（all P>0.05）. There was no significant difference in the incidence of MACCE between the two groups within 30 d after operation（ ?字2=0.006，P=0.983）. The incidence of bleeding events in the bivalirudin group was lower than that in UFH group within 30 d after operation（5.4% vs. 22.9%， ?字2=4.964，P=0.026）. Heparin group showed heparin induced throm－bocytopenia（HIT） one patient. Conclusion：In treatment of aged patients with ACS and CKD3 undergoing PCI，bivalirudin and UFH show similar anticoagulant efficacy. But the effect of anticoagulant efficacy of bivalirudin is more stable，the half-life is shorter，the rate of bleeding is lower，the safety is better，it does not aggravate the impairment of renal function in patients with renal insufficiency.