Adenomatous polyp belongs to the pathological manifestation of intestinal polyp, adenomatous polyp is the main cause of colorectal cancer, patients with family history of colorectal cancer should undergo regular colonoscopy, clinically diagnosed adenomatous polyp, regardless of the size of the polyp must be endoscopically treated, so as to play a role in the prevention of colorectal cancer. The chance of adenomatous polyps becoming cancerous is related to the following factors: 1) Composition: including adenomatous component and villous component, usually those with high content of villous component are prone to cancerous; 2) Diameter: adenomatous polyps with a diameter larger than 2cm are prone to cancerous; 3) Base: those with a wider base are more likely to become cancerous.