Abstract: Objective: Investigating the relationship between polymorphism of GSTM1 and GSTT1 gene and genetic susceptibility to colorectal cancer (CRC). Methods: Genomic DNA of 55 cases with CRC and 62 healthy controls have been used to analysis the genotypes and genetic polymorphism of the GSTM1 and GSTT1 genes by multi-PCR. Results: In healthy control group and CRC patient group, the percentages of GSTM1 null type were 53.2% and 61. 8% respectively, whereas those of GSTT1 were 50.0% and 56.4%. Compared with the healthy control group, the percentage of null types in the patient group was higher, but no significant difference was found. Conclusions: The polymorphism of the GSTM1 and GSTT1 genes may be not related with genetic susceptibility to CRC and to the age of onset at CRC.