Abstract: Objective：To investigate how to discover and treat the resistance of antiplatelet drugs in the patients with the dual antiplatelet therapy after percutaneous coronary interven- tional(PCI) )therapy . Methods: Choose 51 patients who had some change on their skin between those who had received clopidogrel combined with aspirin regularly after PCI . Residual platelet agglutination( RPA )was detect .Patients were divided into aspirin restistance (AR)grup, clopidogrel resistance (CR )group and AR+CR group according to RPA. The patients in AR group had an additional dose of 50mg/d aspirin, those in CR group had an additional dose of 75mg/d clopidogreland those in AR+CR group had a loading dose of 60mg prasugrel followed by a maintenance dose of 10mg/d instead of clopidogrel. RPA was detected and the change on the skin was observed before and 7 days after the treatment . Results: 46 patients had antiplatelet drugs resistance. The occurrence was 90.1%. AR wasnot improved ,but CR and CR+AR were improved after adjusting antiplatelet drugs. The change on the skin also came back to the former state .Conclusion: The resistance of antiplatelet drugs may emerge in patients during the dual antiplatelet therapy after PCI . It can be improved through adding clopidogrel dose or taking prasugrel instead of clopidogrel.