目的：探讨放疗对局限期和广泛期小细胞肺癌化疗疗效的影响。方法：用寿命表法和ＬｏｇＲａｎｋ法分析比较６１例化疗加放疗（化放组）和同期４６例单纯化疗（单化组）小细胞肺癌的生存率。结果：化放组病人１、３、５年生存率分别为７０５％、２５４％和１２９％，而单化组分别为４０７％、２６％和２６％，两组比较有显著差异（Ｐ＜００１）。在局限期病人中，化放组１～５年生存率明显高于单化组（Ｐ＜００２５），而在广泛期病人中，化放组１～５年生存率与单化组无差异（Ｐ＞００５）。结论：放疗能提高局限期小细胞肺癌化疗后的生存率，而对广泛期病人的生存率无影响。 Objective: To investigate the effect of radiotherapy on the curative effect of small and medium-sized small cell lung cancer in a limited period and extensive period. Methods: Survival rates of 61 patients with chemoradiotherapy (chemotherapy group) and 46 patients with chemotherapy alone (chemotherapy group) in small cell lung cancer were analyzed by life table method and LogRank method. Results The 1, 3, 5-year survival rates of patients in the chemotherapy group were 705%, 254% and 129%, respectively, while those in the chemotherapy group were 407%, 2.6% and 2.6% %, There was a significant difference between the two groups (P <001). Among the patients with definite stage, the 1- to 5-year survival rates in the chelation group were significantly higher than those in the singulation group (P <0025). However, in the extensive group, the 1- to 5-year survival rates in the chelation group were significantly lower than those in the chemotherapy group Difference (P> 005). Conclusion: Radiotherapy can improve the survival rate after chemotherapy in patients with localized small cell lung cancer, but has no effect on the survival rate in patients with extensive stage.