摘要Objective: The aim of our study was to investigate the distribution of glutathione-S-transferase M1 (GSTM1) and T1 (GSTT1) gene polymorphism in hepatocellular carcinoma (HCC) and nasopharyngeal carcinoma (NPC) patients in a high risk area in Guangxi Zhuang Autonomous Region, China.Methods: It was a case-control study.The genotypes of GSTM1 and GSTT1 in 181 HCC and 126 NPC patients were compared with 641 matched control.The GSTM1 and GSTT1 genotypes were detected using conventional multiplex PCR method.Results: The frequency of GSTM1 null genotype in HCC, NPC and control groups were 65.2%, 61.9% and 47.6% respectively, significant difference between these two cancer groups and control was observed (P < 0.01).The frequency of GSTT1 null genotype in HCC, NPC and control groups were 57.5%, 62.7% and 43.1% respectively, significant difference between these two cancer groups and control was observed (P < 0.01).Conclusion: The distributions of GSTM1 and T1 genes are polymorphic in HCC and NPC patients in a high risk area in Guangxi, individuals with GSTM1-null or GSTT1-null would have an increasing risk of developing HCC and NPC, especially when combination with virus infection (HBV or EBV) and absorbed chemical toxin (AFB1 or cigarette).