Aim To investigate the cholesterol efflux capacity(CEC) of plasma high-density lipoprotein(HDL) in coronary heart disease(CHD) patients with diabetes and its influencing factors. Methods 140 patients who were diagnosed as CHD by coronary angiography had one or more artery lesion degree ＞50%. They were divided into two groups:the CHD with diabetic mellitus(DM) group(n＝70) and the CHD without DM group(n＝70), patients without CHD confirmed by coronary angiography was taken an controls(n＝25). The capacity of HDL to induce cellular cholesterol efflux was determined by measuring the transfer of [³H] cholesterol from J774 macrophages to the medium containing the ApoB-deleted plasma. The levels of myeloperoxidase(MPO) and serum amyloid A protein (SAA) in plasma were measured to evaluate the level of oxidative stress and inflammation. The correlation between CEC and the above indexes (MPO, SAA) was analyzed. Results The cholesterol efflux capacity in CHD patients with diabetes was significantly lower than that in CHD patients without diabetes (P＜0.05); The level of SAA was increased in CHD patients with diabetes than that in CHD patients without diabetes, but the difference was not statistically significant (P＞0.05). And plasma SAA level in CHD patients with diabetes were negatively correlated with CEC (r＝－0.260,P＜0.05). Moreover, the level of MPO in CHD patients with diabetes was not higher than that in CHD patients without diabetes, there was no correlation between MPO and CEC in CHD patients with diabetes. Conclusion CHD patients with diabetes has more impaired CEC compared with those without diabetes. Inflammation is a possible mechanism of CEC decline caused by abnormal glucose metabolism in patients with CHD.