Objective       To study the expression of human 8-hydroxyguanine deoxyribonucleic acid glycosidase 1（hOGG1）in small cell lung cancer and its correlation with the prognosis of small cell lung cancer patients．     Methods       Expression of hOGG1 was detected by immunohistochemistry in 71 small cell lung cancer tissue samples and 30 normal lung tissue samples. Small cell lung cancer were divided into high expression group and low expression group according to their positive percentage and staining intensity. Correlation of the hOGG1 expression in small cell lung cancer tissue samples with the clinicopathology and prognosis of small cell lung cancer was analyzed.      Results       The hOGG1 was expressed both in small cell lung cancer tissue samples and in normal lung tissue samples. The expression level of hOGG1 was higher in cytoplasm of normal lung tissue samples than in cytoplasm of small cell lung cancer tissue samples（60.0％ vs 49.3％

P0.01）. The hOGG1 was none over-expressed in normal lung tissue samples but in 78.9% of small cell lung cancer tissue samples（P0.01）. The hOGG1 expression was not significantly correlated with gender

tumor staging

smoking index number

lymphatic metastasis or hydrothorax（P0.05）. Kaplan-Meier analysis showed that the hOGG1 expression level was significantly correlated with the prognosis of small cell lung cancer patients（P0.05）. The median survival time of small cell lung cancer patients with a low hOGG1 expression level and a high hOGG1 expression level was 23 months and 13 months

respectively．COX multivariate proportional hazards model analysis indicated that hOGG1 was an independent factor for the prognosis of small cell lung cancer patients（P=0.004）.      Conclusion       The high hOGG1 expression level in cytoplasm is correlated with the occurrence and progress of small cell lung cancer and is one of the poor prognosis indicators of small cell lung cancer patients．