Abstract: Objective : To investigate the association between colorectal cancer genetic sus-ceptibility and the genetic polymorphism of NQ01 NAD (P)H: quinone oxidoreductase 1 gene caused by the point mutation of cDNA 609 C to T. Methods :The polymorphism of NQ01 gene was analyzed in 101 colorectal cancer patients and 103 adult individuals by utilizing PCR-RFLP (polymerase chain reaction restriction fragment length polymorphism) genotyping assay technique. Results : There is a significance difference in the frequencies of the mutated NQ01 genotype (T/ T): 0.327 for cancer patients and 0.175 for control individuals (χ²=9.52, P<0.01). The individuals with the T/T genotype had a increasing cancer risk than individuals with C/C genotypes; the 0R for T/T versus C/C was 3.56 (95: Cl, 1.58-7.96). The frequency distribution of T allele and C allele was 42.1: and 57.3: in cases and 57.9: and 42.7: in controls, respectively (χ²=9.42, P<0.01). The individuals with the T allele had a slight increasing cancer risk than individuals with C allele; the 0R for T versus C was 1.85 (95: Cl, 1.25-2.73). Conclusion : This study may suggest a protect role of the NQ01 wild type(C/C) in the colorectal tumorgenesis and the cDNA 609T allele of NQ01gene may be the risk factor of colorectal cancer. There is also that the indi-vidual's overall susceptibility to colorectal cancer is a consequence of both an inheritable trait inNQ01 metabolism and a behavioral trait in individual living characteristics.