Abstract:【Abstract】Objective To analyze the association of the circadian clock gene (Clock) single nucleotide polymorphism (SNP) with myocardial infarction. Methods 120 patients with myocardial infarction were served as myocardial infarction group, and 78 healthy cases were served as healthy control group. The polymerase chain reaction (PCR), gel electrophoresis and SNaPshot were applied to detect the genotype of Clock. Chisquare test was used to test the genotypic and allelic frequency of Clock gene, and analyzed its association with myocardial infarction in Chinese Han population. Results There was statistical significance in distribution of genotypic and allelic frequency of rs3840267 between myocardial infarction group and healthy control group (P<005). There was no statistical significance in distribution of genotypic and allelic frequency of rs3749474 and rs1402963 between myocardial infarction group and healthy control group (P>005). Conclusion The rs3840267 polymorphism in Clock gene was associated with myocardial infarction.