Abstract： Background Calcified coronary lesions carry the risk of suboptimal stent expansion, subsequently leading to restenosis. The effectiveness of sirolimus-eluting stents (SES) for the treatment of calcified lesion has not been fully investigated. In the present study, therefore, we evaluated the effectiveness of SES Implantation for the treatment of calcified coronary lesions.Mothods A total of 333 consecutive patients with 453 lesions were enrolled in this study. They were divided into two groups according to whether the lesion treated with SES was calcified or not; no calcification group (n=264) and calcification group (n=189). Lesions treated with SES were subjected to quantitative coronary angiography (QCA) immediately and 8 months following stenting.Results Baseline clinical, demographic or angiographic characteristics were well balanced in both groups. Angiographic follow-up at 8 months, the in-stent restenosis and in-segment restenosis rates were not significantly different between the two groups; in-stent restenosis: 3.8% vs 4.2%; P=0.081; in-segment restenosis: 8.7% vs 10.6%, P=0.503. The target lesion revascularization (TLR) was also not significantly different between the two groups; 4.9% vs 6.9%, P=0.378. In addition, the in-stent late loss was similar in both groups; (0.16±0.40) mm vs (0.17±0.33) mm, P＞0.05. Meantime, overall thrombosis rates were also similar in both groups; 1.6% vs 1.6%, P＞0.05.Conclusion Although calcified coronary lesion was hard to stent, successful percutaneous coronary intervention with SES stenting for calcified lesions was conferred by the similar favorable results that were seen when comparing non-calcified and calcified coronary lesions.