Objective To investigate the characteristics of coronary vessel re-endothelialization after placement of drug-eluting stents (DES), and to provide clinical evidence for the double anti-platelet treatment. Methods Optical coherence tomography (OCT) was performed in 43 patients in 1 year after DES implantation. Characteristics of re-endothelialization and percentage of neointimal coverage of stent struts were evaluated by OCT. Results The rate of stent struts intimal coverage was 90.70%, and the remain was lack of endothelial coverage; The ratio of neointimal thickness (NIT) between 0-99, 100-199 and above 200 microns was 19.92%, 37.55% and 42.53%, respectively. The rate of neointimal coverage was higher and the degree of neointimal hy-perplasia was more extensive in patients with DM and in patients with ACS than those of patients without DM and of patients with stable angina pectoris. Conclusion One year after stent placement, most of the stent struts were covered with neointima and few struts obtained poor coverage of endothelial. DM and ACS may be impact factors for the progress of re-endothelialization after DES placement.