Objective To analyze the expression of excision repair cross-complementation group 1 (ERCC1),MutS protein homolog 2 (MSH2) and poly ADP-ribose polymerase 1 (PARP1) in non-small cell lung cancer (NSCLC) and their prognostic value for patients receiving platinum-based postoperative adjuvant chemotherapy.Methods Immunohistochemistry was applied to detect the expression of ERCC1,MSH2 and PARP1 in 111 cases of NSCLC paraffin embedded surgical specimens.Through OG-Rank survival analysis,the prognostic value of the ERCC1,MSH2,PARP1 and the related clinic pathological factors were evaluated.Cox regression analysis was used to determine whether ERCC1,MSH2 and PARP1 were independent prognostic factors or not.Results Among the 111 NSCLC patients,the positive expression rates of ERCC1,MSH2 and RARP1 were 33.3 ％(37/111),36.9 ％(41/111) and 55.9 ％(62/111),respectively.Besides,a total of 72 patients who received platinum-based chemotherapy had complete follow-up data.ERCC1 (P＜ 0.001) and PARP1 (P=0.033) were found to be correlated with the survival time while there was no correlation for MSH2 (P =0.298).Patients with both ERCC1 and PARP1 negative had significant longer survival time than those with ERCC1 (P=0.042) or PARP1 (P=0.027) positive alone.Similarly,the survival time of patients with both ERCC1 and PARP1 positive was shorter than those with ERCC1 (P=0.048) or PARP1 (P=0.010) positive alone.Conclusions The NSCLC patients with ERCC1 and (or) PARP1 negative may benefit from platinumbased postoperative adjuvant chemotherapy.The detection of ERCC1 and PARP1 can be used as an important method to assess the prognosis of patients with NSCLC.