Abstract: Objective 　To discovery the major risk factors of colonic cancer and provide some reference for proper interventions of colonic cancer. Methods 　A case2cont rol study including cases and cont rols, who were matched by age and gender, was carried out in the three hospitals of Cent ral South University. Fac2 tors were analyzed using conditional logistic regression. Results 　As the result s of multivariate regres2 sion, f requently being in sitting, animal oil is the primary part of cooking oil, cystic diseases, appendicitis and cancer history of first degree relatives were risk factors of colonic cancer, while f requently eating veg2 etable were protective factors of colonic cancer. Conclusion 　The life style and dietary habits, digestive dis2 eases and the positive history of cancer in relatives were the major influencing factors of colonic cancer.