Objective To observe the change of serum leptin in different risk stratifications of coronary heart disease (CHD) and to investigate its relationship with the severity of coronary artery lesion and the coronary artery Gensini score and its value in the coronary heart disease risk stratification .Methods According to coronary angiography ,120 research subjects were enrolled and di-vided into 4 groups :the non-CHD group ,stable angina(SAP) group ,unstable angina pectoris(UAP) group and myocardial infarc-tion group(AMI) ,respectively .The serum leptin levels in 4 groups were determined by immunoassay and the correlation between the leptin level with the coronary heart disease risk factor and biochemical markers of risk assessment was analyzed .Results The serum leptin level in the AMI group was significantly higher than that in the non-CHD group and the SAP group ,the leptin level showed the increasing trend with the increase of the coronary lesion severity and the Gensini scores and was positively related with the CHD risk stratification indicators cTnT and smoking index ,and negatively related with blood uric acid .Conclusion The serum leptin may be used as the valuable marker for evaluating the occurrence of acute coronary event and has good correlation with usual biochemical markers of CHD risk stratification and the severity of coronary artery lesion .