Platinum-based chemotherapeutics are the most common regimens for advanced non-small-cell lung cancer (NSCLC) patients. However, it is difficult to identify platinum resistance in clinical treatment. Genetic factors are thought to represent important determinants of drug efficacy. In this study, we investigated whether singlenucleotide polymorphisms (SNPs) in human mutS homolog 2 (hMSH2) and the human mutL homolog 1 (hMLH1) were associated with the tumor response in advanced NSCLC patients received platinum-based chemotherapy in Chinese population. Totally, 96 patients with advanced NSCLC were routinely treated with cisplatin- or carboplatin-based chemotherapy. The three-dimensional (3D), polyacrylamide gel-based DNA microarray method was used to evaluate the genotypes of hMSH2 gIVS12-6T/ C and hMLH1-1151T/A with peripheral lymphocytes. We found that there was a significantly increased chance of treatment response to platinum-based chemotherapy with the hMSH2 gIVS12-6T/C polymorphism. The 3D polyacrylamide gel-based DNA microarray method is accurate, high-throughput, and inexpensive, especially suitable for a large scale of SNP genotyping in population.