Abstract: Objective:To investigate the glutathione S-transferase gene(GSTMl) missing and environmental factors associated with lung cancer.Methods:A case-control study,investigated 150 cases of lung cancer patients hospitalized and 150 healthy cases,as living habits and family history information,and detected the GSTM1 genotype by PCR-RFLP,Logistic regression analysis the association between GSTMl,smoking factor and lung cancer,and the interaction between the GSTM1 and smoking factor.Results:(1) The rate of GSTMl(-) in case group was 64.0%,thus was 45.3% in control group,the risk of GSTM1 gene deletion for lung cancer OR value was 2.14(95% CI:1.35～3.41);factors of smoking for lung cancer OR value was 2.53(95% CI:1.57～4.06);(2) The OR value of GSTMl(-) joint smoking factor for lung cancer was 5.58(95% CI:2.71～11.49),which was greater than the product OR value of smoking and the GSTMl(-),the interaction might be ultra-multiplication model;(3) With the increase in the amount of smoking,the interaction coefficient γ values were 2.315,2.088,2.035 increasely.Conclusion:The GSTMl(-) genotype and smoking factor were associated with lung cancer,GSTMl(-) genotype and smoking factors exist between the interaction of ultra-multiply mode,GSTMl(-) genotype with cigarette smoking exposure was low-gene effect.