Objective To analyze non -small cell lung cancer patients with platinum -based chemotherapy excision repair cross -complementing 1 (ERCC1)and breast cancer susceptibility gene 1 (BRCA1 )gene polymor-phism,to examine the correlation of ERCC1 and BRCA1 gene polymorphism and non -small cell lung cancer platinum chemotherapy drugs sensitivity and chemotherapy prognosis.Methods 140 cases of non -small cell lung cancer were selected as subjects of this study.All patients were given platnum -based chemotherapy,peripheral blood ERCC1 and BRCA1 genes polymorphism were determined.The distribution of ERCC1 Asn118Asn genotype and BRCA1 Ser1613Gly genotype was observed.The relationship between different genotypes and the effect of chemotherapy and survival time after chemotherapy was compared.Results The proportions of ERCC1 Asn118Asn TT genotype,CT genotype and CC genotype were 5.7%,30.7% and 63.6%.The proportions of BRCA1 Ser1613Gly GG genotype,AG genotype and AA genotype were 8.6%,52.9% and 38.6%.In 140 patients,completely cured,partial response,stable disease and progressive disease patients were 0 case,33 cases,61 cases and 46 cases,the proportions were 0.0%, 23.6%,43.6% and 32.9%,the chemotherapy effective rate was 33.8%.ERCC1 Asn118Asn genotype was signifi-cantly correlated with the effect of non -small cell lung cancer chemotherapy (χ2 =4.416,P <0.05 ).BRCA1 Ser1613Gly genotype was significantly correlated with the effect of non -small cell lung cancer chemotherapy (χ2 =13.256,P <0.05).By Cox regression analysis and Log -rank test analysis,the average survival time of BRCA1 Ser1613Gly gene CC genotype non -small cell lung cancer after chemotherapy was longer than the CT +TT genotype (OR =2.946,χ2 =5.136,P <0.05).The average survival time of BRCA1 Ser1613Gly gene AA genotype non -small cell lung cancer after chemotherapy was shorter than the AG +GG genotype (OR =3.124,χ2 =5.136,P <0.05).Conclusion ERCC1 Asn118Asn genotype and BRCA1 Ser1613Gly genotype was significantly correlated with non -small cell lung cancer platinum -based chemosensitivity and chemotherapy prognosis.