Objective: The present study aimed to investigate the relation between CYP2C19 gene polymorphism and ADP-induced platelet aggregation ratio (MAR) in patients with coronary heart disease (CHD) administrated with clopidogrel. Methods: 1251 CHD patients were admitted to the Heart Center of the First Affiliated Hospital of Xinjiang Medical University from January 2011 to June 2017 were included the present study. CYP2C19 genotype and ADP-induced platelet aggregation rate were detected after given loading dose of 300 mg clopidogrel for 24 hours. We observed the relation between CYP2C19 genotype and platelet aggregation rate after loading clopidogrel. Results: CYP2C19 genotyping results showed that 608 (48.6%), 515 (41.1%) and 128 (10.2%) patients were extensive metabolism (EM, CYP2C19 *1/*1), intermediate metabolism (IM, CYP2C19*1/*2, *1/*3) and poor metabolism (PM, CYP2C19*2/*2, *2/*3, *3/*3) carriers, respectively. Platelet function test results showed that there were 60.5% of patients with on-treated high platelet response (MAR ≥ 55%). Nevertheless, we did not find any association of MAR with CYP2C19 in the present study. Conclusion: The present study indicated that both on-treated high platelet response patients and CYP2C19 PM carriers are frequent in CHD patients in China. However, there was no association of MAR after 300 mg of loading clopidogrel with CYP2C19 genotypes.