485 lymph nodes were founded by palpation in 44 R3 resected specimens of colonic cancers. In the bowel axial direction, the rate of lymphatic metastasis was 6.8%, which accound for 9.6% of the positive lymph node metastasis. All these positive nodes were limited from 10 cm proximal to 5 cm distal to the tumor. In the central direction, the rate of mesenteric lymphatic metastasis was 20.4%, and the rate of lymphatic metastasis at the root of mesentery was 4.5%, which accounted for 38.1% of the positive lymph node metastasis. Compared to the bowel axial direction, mesenteric lymphatic metastasis in the central direction was more common and should be carefully disseted during radical operation.