TNM staging criteria of colon cancer are mainly based on three criteria: primary tumor status, lymph node metastasis and distant metastasis to determine the clinical stage of colon cancer. 1.T stands for primary tumor (1)Tx is the primary tumor cannot be assessed. (2)T0 is no primary tumor. (3)Tis the intraepithelial or invasion of the mucosal lamina propria of the primary tumor. (4) T1 is tumor invading the submucosal layer. (5) T2 is tumor invasion of the lamina propria. (6) T3 is tumor reaching the subplasma layer or infiltrating into pericolonic tissues not covered by the peritoneum. (7) T4 is the tumor penetrating the plasma membrane of the visceral layer or invading other organs and tissues. 2.N for regional lymph nodes (1)Nx stands for regional lymph node whether metastasis cannot be assessed. (2)N0 represents regional lymph nodes without metastasis. (3)N1 represents 1-3 lymph nodes with metastasis. (4)N2 represents 4 or more lymph node metastases. (5) N3 represents any supra-rectal paravascular lymph node metastasis 3.M for distant metastasis (1)Mx represents the absence of distant metastasis, which cannot be assessed. (2)M0 means no distant metastasis. (3) M1 means distant metastasis. When colon cancer is present, it is necessary to actively consult the doctor and follow the doctor’s instructions for reasonable treatment.