Stratification by tumor site indicated that the GSTM3 polymorphism was associated with a decreased risk of laryngeal cancer under recessive model and homozygote comparison (OR = 0.52, 95%CI: 0.30-0.89; and OR = 0.50, 95%CI: 0.29-0.87, respectively); By stratifying source of control, decreased cancer risk was observed in hospital-based population under all genetic models (OR = 0.67, 95%CI: 0.56-0.81 for the dominant model; OR = 0.66, 95%CI: 0.46-0.95 for the recessive model; OR = 0.55, 95%CI: 0.37-0.83 for the homozygote comparison model, and OR = 0.70, 95%CI: 0.58-0.84 for the heterozygote comparison model).