Abstract: Objective 　This study examined the association between genetic polymorphisms of XRCC1 and response to cisplatin- or carboplatin- based chemotherapy of advanced non-small cell lung cancer (NSCLC) . Methods 　Totally 97 patients with advanced NSCLC were routinely treated with cisplatin- or carboplatin- based chemotherapy, and clinical response was evaluated af ter 3 cycles. XRCC1 genotypes were determined by PCR-RFLP methods using DNA samples isolated from peripheral blood collected before treatment . Results 　(1) The response rate to the chemotherapy in patients with the XRCC1 194Arg/Trp genotype significantly higher than that in patient s with the Arg/ Arg、Trp/ Trp genotype ( P < 0. 05) ;The XRCC1 194 Trp allele carriers had higher response rate than the subjects with the Arg/ Arg genotype (adjusted OR = 3. 39, 95 % CI = 1. 32～8. 70, P < 0. 05) . There was no difference of the response rate (34. 6 %、27. 5 %, 20. 0 %) to chemotherapy with the 399 Arg/ Arg、Arg/ Gln、Gln/Gln gene type ( P >0. 05) . Furthermore, it did not appear that 194Arg/ Trp and 399Arg/ Arg genotypes had synergic effect on the chemotherapy efficacy. Conclusion 　Polymorphisms in the XRCC1 Arg194 Trp may have significant impact on the response of NSCLC patient s to platin-based chemotherapy.