For those with one or more of the above manifestations, the possibility of small intestinal tumor should be considered and further examination is needed. 1.X-ray barium meal examination, for the tumor suspected to have duodenum, relax duodenal barium radiography was used. 2. Fiberoptic duodenoscopy, fiberoptic enteroscopy and selective arteriography can improve the diagnostic rate of small intestinal tumors. 3. Because of the increase of 5- hydroxytryptamine in the blood of carcinoid patients, it is helpful to determine the nature of tumors by measuring 5- hydroxyindoleacetic acid (5-HIAA), a degradation product of 5-hydroxytryptamine in the urine of patients with suspected carcinoid diseases. 4. If necessary, exploratory laparotomy is feasible.