Objective:To investigate the impact of GSTT1 and GSTM1 genotypes on early treatment response and chemotherapy toxicities of childhood acute lymphoblastic leukemia(ALL). Methods:GSTT1 and GSTM1 genotypes were analyzed with PCR in 98 ALL patients. The early treatment response and chemotherapy toxicities were compared between groups with or without GSTT1 and GSTM1 genes. Results:Patients without GSTT1 gene had better early treatment response than patients with GSTT1 gene(OR=3.35,95%CI:1.05-10.73,P=0.041). The risk of poor early treatment response in patients with GSTT1 and GSTM1 double present was much higher than that in patients with GSTT1 null or GSTM1 null(OR=5.73,95%CI:1.73-18.95,P=0.004). The risk of oral mucositis,heptatoxicity and infection in patients with GSTM1 null was higher than that in patients with GSTM1 present(P < 0.05). Patients without GSTT1 and GSTM1 genes experienced more heptatoxicity and infection than patients with GSTT1 and GSTM1 genes(P < 0.05). Conclusion:GSTT1 and GSTM1 genotypes were apparently related to early treatment response and chemotherapy toxicity of patients with ALL. GSTT1 and GSTM1 genotypes might be useful in selecting appropriate chemotherapy regimens for patients with ALL.