Abstract: Objective To analyze the long-term effect and safety of drug-eluting stent in patients with coronary heart disease (CHD)accompanying diabetes mellitus (DM). Methods Six hundred and forty-six patients who underwent drug-eluting stenting in our hospital from January 2005 to December 2008 were divided into CHD with DM group (n=192) and CHD without DM group (n=454) .Of the 192 patients in CHD with DM group, 183 (95.3%) were followed up. Of the 454 patients in CHD without DM group, 428(94.3%) were followed up. The incidence of major adverse cardiac events (MACE) was recorded in these followed up patients after drug-eluting stenting. Results The incidence of hypertension and lesions of 3 coronary branches was higher in CHD with DM group than in CHD without DM group (75.4% vs 60.5%, P=0.00; 47.0% vs 37.6%, P=0.05). The proportion of female patients was higher in CHD with DM group than in CHD without DM group (26.2% vs 16.6%, P=0.01). The average age of CHD with DM group was younger than that of CHD without DM group 60.08±11.58 years vs 64.01±10.79 years, P=0.00). No significant difference was found in the incidence of MACE between the two groups. However, the incidence of MACE tended to increase with the time after operation in the two groups. The incidence of stent thrombosis was higher in CHD with DM group than in CHD without DM group (2.7% vs 0.2%, P=0.02). Conclusion The proportion of patients with CHD accompanying DM is higher than that of those not accompanying DM. The incidence of stent thrombosis is higher in patients with CHD accompanying DM than in those not accompanying DM. The incidence of MACE tends to increase after drug-eluting stenting, especially after 5 years.