Abstract: The case-control study was conducted to examinethe association between GSTM 1 null and CYP2D6Ch(T188 /T) genotypes and lung cancer risk among Chinese of Han nationality living in Guang dong. GSTM 1(-) was detected with polym erase chain reaction(PCR) in all 191 subjects, involving 59 lung cancer cases, 59 hospital controls and 73 healthy controls. The frequencies of GSTM 1(-) were not significant difference between the cases and thetwo controls overall. However, among adenocarcinoma of lung, the frequency of GSTM 1(-)(76. 9%) was higher than that in controls(49. 2%), and the odd radios were 3.42～3.45. The results suggested an elevated risk for adenocarcinoma of Lung with GSTM 1(-). Polymerase chain reaction-restriction fragment length polym orphisms(PCRRFLP) was used to etect CYP2D 6C h(T188/T) genotype in 59 lung cancer patients and 59 hospital controls, and not significant difference between thetwo groups. However, nonsmokers with non-T188/T(C188 /C or C188 /T) genotypes had 3.78-fold increased risk of lung cancer compared to those with T188/T genotype(with P= 0.036). No result suggested a substantial interaction effect between GSTM 1 and CY P2D6 polym orphisms and the risk of lung cancer.