〔Abstract〕 Objective To explore the association between mammalian sterile 20-like kinase 1(MST1) gene polymorphism and haplotype and the risk of colorectal cancer, rectal cancer, and colon cancer in the Han population in Baotou area by case-control association study. Methods A total of 390 patients with colorectal cancer diagnosed by pathology and 413 normal physical examination population were collected, and 2 ml of peripheral blood was taken for subsequent gene genotyping. Single nucleotide polymorphisms(SNPs) ofMST1gene were screened according to the genetic polymorphism data of Chinese Han population provided by the National Center for Biotechnology Information-Haplotype Mapping database. Gene genotyping was performed by Taqman method. Logistic regression was used to calculate the association between each SNP and the risk of colorectal cancer, colon cancer, and rectal cancer under codominant, dominant, overdominant, and recessive genetic models. Results Four SNPs ofMST1gene were screened, namely rs8000, rs2234197, rs2267853, and rs6073629. Among them, SNP rs2234197 was associated with the risk of rectal cancer. Compared with the GG+AA genotype, the AG genotype could reduce the risk of rectal cancer, OR[95%confidence interval(CI)] =0.657(0.442-0.976). SNP rs8000 was associated with the riskof colon cancer. Compared with the TT+GT genotype, the GG genotype could reduce the risk of colon cancer [OR(95%CI)=0.425(0.182-0.992)]. Conclusion MST1gene SNP rs2234197 AG genotype and SNP rs8000 GG genotype may be protective factors for rectal cancer and colon cancer, respectively.