Abstract: AIM:To explore the influential factors of clopidogrel resistance in patients with coronary heart disease (CHD) who received percutaneous coronary interventions (PCI). METHODS: A total of 159 patients with CHD who underwent PCI were enrolled. Clopidogrel of 300 mg loading dose and 75 mg/day ongoing dose was administered before and after PCI. The 5 μmol/L adenosine diphosphate (ADP)induced maximum platelet aggregation rate (MPAR) was tested before administration as well as 24 h and 5 days after PCI. Patients were divided into clopidogrelresistant group (platelet aggregation rate ≤10%) and normal response group. Basic clinical data, related routine examination results, MARP and PCI characteristics were compared between groups and the independent risk factors of clopidogrel resistance were explored by logistic regression analysis. RESULTS: The incidence of clopidogrel resistance after PCI was 30% (40/159) in the 159 patients under study. Significant differences were found in patients with a long history of smoking, history of diabetes and triglyceride levels between groups (P<0.05), whereas no significant difference was observed in the PCI characteristics between groups. Logistic regression analysis revealed that history of diabetes and long history of smoking were independent risk factors of clopidogrel resistance but PCI characteristics were not related to clopidogrel resistance. CONCLUSION: Diabetes and long history of smoking may be risk factors for clopidogrel resistance in patients with CHD after PCI.