Aim To study the relationship between Cytochrome P450 2C9(CYP2C9) gene polymorphism and coronary heart disease(CHD) and to investigate if there is the effect of CYP2C9 gene polymorphism on plasma lipid levels. Methods The polymerase chain reaction and gene sequence detection were used to detect CYP2C9 genotypes in 218 CHD cases and 200 controls.Plasma lipid levels were measured by using routine method. Results Statistical differences in CYP2C9*1 and CYP2C9*3 frequencies between CHD cases and controls were seen(P<0.05).The frequency of CYP2C9*3 was significantly higher than that in controls.Unfortunately,no relationgship was seen between CYP2C9 gene polymorphism and plasma lipid levels. Conclusion These results suggest that CYP2C9 gene polymorphism is in association with the occurrence and development of CHD. But it does not affect the plasma lipid levels.