 All the patients with colon cancer will undergo elective radical operation. The observations were recorded during the operation and on the postoperative specimens. Intra-operative photographs were taken at various stages, as were photographs of the postoperative specimen. According to the CME operation keypoints, all the photographs will accept third-party assessment of the expert group, while the third-party expert group will not participate in the management of patients. Both of The evaluators and research doctors are double-blind state. The postoperative patients will divided into two groups according to the results of the assessment. The clinical and pathological data of the patients as well as follow-up information will be recorded and collected. 