Abstract: Objective :The aim of this study was to analyze the association of phase Ⅱ metabolism glutathione S-transferase mu gene (GSTM1) and mutations of p53 gene in the patients with lung cancer. Methods :GSTM1 polymorphisms were determined by the multi -differential polymerase chain reaction (MD-PCR) method.The polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) was performed for detection of point mutations at exons 5-8 of the p53 gene. Results :The deletion (null phenotype) rate of GSTM1 in lung cancer patients was significantly higher than that in control groups,71.4% (45/63) and 51.1P (24/47), respectively. The odds ratio associated with GSTM1 null genotype was 2.40 (95% confidence interval 1.09,2.59).Lung cancer patients showed a higher rate (49.2%, 31/63) of p53 gene mutation than the control group (6.6%, 1/15) and 58.1% (18/31) of lung cancer patients showed the combined deletion of GSTM1. Conclusion :We conclude that GSTM1 deletion associates with p53 gene mutation in lung cancer. GSTM1 deletion increased the risk of lung cancer appears to be mediated through the mechanisms to p53 expression.