The cytochromes P450 epoxygenases CYP2J2 synthesize epoxyeicosatrienoic, which regulate endothelial function. The aim of this study was to assess the association between the human CY2J2 gene and myocardial infarction (MI) in a Chinese population using a haplotype-based case-control study. There were 440 Chinese Han MI patients and 440 age-matched control subjects genotyped for three SNPs (rs2271800, rs11572223, and rs14493270) of the human CYP2J2 gene. Haplotypes were constructed and their frequencies compared between the MI patients and the controls. The CC genotype of rs2271800 was found more frequently in the MI group than in the control group (p = 0.004). The frequency of the C-C-G haplotype was significantly higher in MI patients than in control subjects (p < 0.001). The present results indicate that MI is associated with the CC genotype of rs2271800 in the human CYP2J2 gene. The C-C-G haplotype appears to be a useful genetic marker of MI in Chinese Han people.