Abstract: Objective To observe the therapeutic efficacy of chemotherapy and the concurrent chemo-radiotherapy in treatment of extensive stage small cell lung cancer(ES-SCLC). Methods We retrospectively analyzed 68 patients with ES-SCLC.Among them, 40 patients received chemotherapy(CT)and concurrent local radiotherapy at the end of the fourth CT cycle;the other 28 patients only received chemotherapy.Both groups used the EP-CAV regimen for six cycles.Results The short-term therapeutic effect:responsive rates of combined group and CT group are 82.5% and 57.2%, respectively(P＜0.05).The long-term therapeutic effct:the one-year survival rates are 52.5% for combined group and 28.6% for the CT group( P＜0.05).The two-year survival rates are 20% and 7.14%, respectively(P＞0.05).The median-survival time are 13 months in combined group and 8 months in CT group.Conclusions The short term therapeutic effect and one-year survival rate of the combined group are better than that of CT group(P＜0.05), the differences are significant.The difference of two-year survival rate is not significant, but the combined group showed better survival tendency.