Abstract: Objective： To observe the efficacy and safety of ticagrelor in the treatment of acute coronary syndrome(ACS) patients combined with chronic renal insufficiency(CRI)undergoing percutaneous coronary intervention(PCI).Methods： 426 ACS patients who received PCI from October 2014 to October 2015 were divided into normal renal function group(A group，n=195 cases) and renal insufficiency group(B group，n=231 cases).All the patients were given ticagrelor for 12 months，loading dose of 180mg followed by 90mg bid. Major adverse cardiac and cerebrovascular events(MACCE)， bleeding events and adverse reacitons were compared between the two groups. Results： After 12 months of treatment， in the incidence of MACCE， there was no significant difference between the two groups(P>0.05). No major bleeding happened during the experiment.58 bleeding cases occurred in B group(including 3 cases moderate bleeding and 55 cases minor bleeding)， more than 42 cases in A group (including 1 cases moderate bleeding and 41 cases minor bleeding). However， there were no significant differences in incidence of bleeding between the two groups(P>0.05).22 cases（11.3%）dyspnea occurred in A group and 29 cases（12.6%）in B group， dyspnea in both the groups was mild， tolerable and temprorary， there were no significant differences in incidence of dyspnea between the two groups(P>0.05).Conclusion： Ticagrelor is an effective and safe drug in the treatment of ACS patients combied with CRI.