Desmoid tumor （DT）, a rare benign tumor sometimes with local invasion, is more frequently seen in patients with familial adenomatous polyposis （FAP） than in the general public, which might be associated with surgical trauma, genetic predisposition and hormonal factors. Fifty percent of FAP-associated DTs are intra-abdominal, usually present as non-tender, slowly growing masses. The symptoms include abdominal pain, vomiting and diarrhea, etc. Mesenteric DT can cause obstruction and ischemia of intestine, hydronephrosis and fistula, Diagnosis can be made through biopsy or CT scanning. Surgery should be considered for the abdominal wall DTs and medicine is the first choice for mesenteric DTs, Surgery should be chosen with caution