Abstract: Objective :To investigate the relationshp of survival time and expression of pl6,Rb,cylinDI and PCNA in lung cancer. Methods :Immunohistochemical techniques were applied to study the expression of PCNA,p16,pRB,cydinDI.The results were analyzed by Cox-Model and single factor Kaplan-Meier assay., Results :1.the PCNA protein was expressed in all lung specimens (65 specimens ) with different level.The expression of NSCLC were stronger than that of SCLC (P<0.05).The high expression of PCNA was correlated with p16 negative, pRB positive,p^tumor status and distant metastasis.The high PI was correlated with poor prognosis (survival time≥24 months) being 81.82 percent for PI (PCNA index)I-II and 18.18 percent for PI III-VI respectively,p<0.01.2.The positive rate of p16 (50.77%) was correlated with differentiation degree of adenocarcinoma,the higher differentiation, the higher positive rate (P<0.01).But as far as squamous cell carcinomas was concerned,it had no relationship with differentiation. The survival time ≥24 months of patients with p16 negative and p16 positive was 72.73% and 27.27%, respectively(P<0.05). The positive rate of pRB (58.46%) in NSCLC were significantly more than that of SCLC.The positive rate of cylinDI was 60%, squamous cell carcinomas 72.41%,adenocarcinoma 58.33 percent,SCLC 25.00 percent respectively.A statistical significant difference existed among the three kinds of lung cancer. 3 Cases with p16-pRB+ had a higher cell proliferation activity and shorter survival time. So did for cases with cylinDI+ p16-pRB+. Conclusions :PCNA and p16 were independent markers for progress of lung cancer.When PCNA 、p16、pRB and cyclinDI were detected together.This was the most relevant conbination of alterations contributing to prognosis.Lose of pRB expression in SCLC suggest that it is different from NSCLC diognostidy.