Abstract: ObjectiveTo investigate genetic association between N-acetyltransferase-2(NAT2)gene polymorphism and colorectal cancer(CRC).MethodsA hospital-based 1:2 matched case-control study and PCR-based ligase detection reaction(PCR-LDR)were applied to tag single nucleotide lengh polymorphism(SNPs)of NAT2 gene among 104 cases with colorectal cancer and 208 controls.ResultsThe genotypic frequency of tag SNPs of NAT2 gene did not deviate from Hardy-Weinberg equilibrium in both case and control groups.Rs1799931 was not associated with colorectal cancer(P>0.05),but rs1799929 and rs1799930 were related to colorectal cancer(P<0.05).The case group had more T allele of rs1799929 and A allele of rs1799930 when compared to the controls;while T allele of rs1799929 and A allele of rs1799930 seemed to be the risk factors of colorectal cancer(odds ratioOR=2.069, P=0.004;OR=1.431, P=0.004).The frequency of NAT2 slow genotype was 43.3% in the cases compared with 26.0% in the controls.As compared with the NAT2 rapid genotypes,the NAT2 slow genotype significantly increased the risk of developing colorectal cancer,with an OR of 1.667(95% confidence interval:1.213-2.291).ConclusionThe results suggest that NAT2 genetic polymorphism is associated with colorectal cancer susceptibility.People with NAT2 slow genotype have a higher risk of colorectal cancer.