Circumferential resection margin(CRM) is the closest distance from the deepest of tumor invasion to the surgical margin of mesentery. It has been well known that CRM has significant impact on the prognosis and treatment of rectal cancer. However, the significance of CRM of colon cancer is just brought to the forefront recently. Current evidence showed positive rate of CRM is 10%, and the patients with positive CRM have worse survival. The factors influencing CRM include tumor stage, differentiation, vascular cancer embolus, etc. Standard surgical procedure can lower the positive rate of colon CRM, and adjuvant therapy applied to the patients with positive colon CRM can improve the survival of colon cancer patients. CRM may become a new factor guiding the treatment in colon cancer patients.