Abstract: Objective :To study the genetic polymorphism of cytochrome P450A1 (CYP1A1),GSTM1 as susceptibility factors for lung cancer. Methods :The genetic polymorphism CYP1A1 andGSTM1 were performed in all lung cancer patients and controls using restriction fragment length poly-morphism-polymerase chain reaction (RELP-PCR) methods. Results :The significant differences fordistributions of CYP1A1 and GSTM1 genotype were observed between lung cancer patients and controls(P<0.05).The individual who carried CYP1A1 variant or GSTM1 negative genotype had an increasedrisk for lung cancer, the odd ratio (OR) were 2.44 (1.04~5.81) and 1.84 (1.03~3.29), respectively. Mul-tivariate analysis showed an elevate risk for lung cancer in subjects having CYP1A1 variant genotype,GSTM1 negative genotype and smoking. Conclusion :The genotype of CYP1A1 variant, GSTM1 nega-tive are susceptibility factors of lung cancer and probably interacts with smoking.