Abstract: Objective: To determine the predictive values of Top II α and Ki67expression in postoperative stage I-III non-small lung cancer patients who received adjuvant chemotherapy. Methods:Non-small cell lung cancer cases who re-ceived surgical therapy in our hospital between January 2004and December 2007were analyzed. Cases with no follow up or who couldn’t finish at least one cycle of adjuvant chemotherapy were not recruited. Paraffin-embedded samples of 152 cases were col lected for immunohistochemical detection of Top II α and Ki67expression.Results: The expression rates of Top II α and Ki67were22.4% and 36.2% , respectively. Top II α expression was posi tively correlated wi th Ki67expression (r= 0.516 , P<0.001 ). By the end of the study, 41patients had died. The overall survival (OS) was not available. The median dis -ease free survival (DFS) was 23.0 months. In univariate survival analysis, sex, clinical stage, N stage, adenocarcinoma and expression level of Top II α were related to DFS, whi le age, smoking, chemotherapy regimens and expression level of Ki67 were of no prognostic significance. Factors indicating better DFS were male gender (P=0.041 ), earlier clinical stage ( P=0.001 ) or N stage (P<0.001 ), nonadenocarcinoma (P=0.003 ) and over-expression of Top II α (P=0.011 ). We further strati-fied for expression levels of Top II α and Ki67. In weak expression of Top II α strata, the regimen wi th NVB had prolonged DFS compared with the other regimens, but there was no statistical significance (P=0.059）. And in weak-expression of Ki 67strata, the regimen with NVB had prolonged DFS compared with TXT regimen (P=0.033 ). However, there was no simi-lar prognostic signi ficance in over-expression of Top II α or Ki67strata. In COX proportional regression, presence of N stage adenocarcinoma and expression level of Top II α were independent risk factors affecting the prognosis of DFS. Conclusion: Over-expression of Top II α contributes to DFS of postoperative NSCLC patients who received adjuvant chemotherapy. The regimen wi th NVB is more effective than other regimens in improving DFS in weak-expression of the Top II α group, where-as the regimen with TXT is less effective than others in weak-expression of the Ki67group. Top II α can be considered as a new biomarker to predict the effect of adjuvant chemotherapy and is helpful for the selection of a better chemotherapy regi-men for postoperative NSCLC patients.