Objective: to determine the role of excision repair cross-complementing group 1 gene(ERCC1)and ribonucleotide reductase subunit M1(RRM1)expression in predicting response and survival in Chinese patients with advanced stage non-small cell lung cancer(NSCLC)treated with platinum-based chemotherapy.Methods: Formalin-fixed,paraffin-embedded biopsy tissues were retrospectively obtained from 160 advanced NSCLC patients,mRNA expression levels of ERCC1 and RRM1 were determined by real-time PCR.Results: Associations between mRNA expression level of ERCC1 and RRM1 and clinic-pathologic parameters were analyzed.One handred and forty two(88.75%)specimens were successfully amplified,mRNA expression level of ERCC1 and RRM1 was negatively associated with tumor response.ERCC1 expression levels ranged from 0.01 to78.79[median 0.63,mean 4.25 and standard deviation(SD)9.23]and RRMI from 0.00 to 30.91(median 0.63,mean0.87 and SD 3.36).By adopting cut-off values according to median expression levels,we found that MST in patients with low ERCC1 mRNA levels was significantly longer in overall population than in patients with higher levels(18.63versus 13.69 months,log-rank 5.73,P=0.017),but we did not found the survival benefit of the patients with low expression level of RRM1.(19.07 versus 14.88,log-rank 1.66,P=0.197).Further,in the muitivariable Cox regression model analysis we found that low level of ERCC1 expression,the presence of weight loss and target therapy,were significant prognostic factors for survival.Conclusion: ERCC1 expression is associated with patients' survival in Chinese advanced NSCLC patients treated with platinum-based regimen and may serve as a biomarker in predicting tumor response and clinical outcome in the patient population.