【Abstract】ObjectiveTo study the diagnosis and the treatment of gastrointestinal stromal tumor (GIST). Methods In this retrospective study, tissue slices, including immunohistochemical examinations, of 48 patients with GIST from January 1999 to December 2004 were collected. All of their clinical symptoms, pathologic characters, and surgical treatment and other information were also analyzed. ResultsTwenty-seven males and 21 females with a mean age of 68 were included in this report. All patients received tumor resections. Tumors were located in the stomach in the 29 cases (60.4%), and 11 cases (22.9%) were in the small intestine. The main clinical manifestations were alimentary tract hemorrhage (52.1%) and abdominal mass (35.4%). Immunohistochemical examination showed the positive rate of CD117 was 83.3%(40/48), and CD34 was 77.1%(37/48). Conclusion GIST mostly occurs at stomach and small intestine in aged people with clinical manifestations of alimentary tract hemorrhage and abdominal mass. The diameter of the mass is an important clinical index to distinguish malignant and benign tumors. The diagnosis of GIST depends on the combination of pathological and immunohistochemistry examinations. Complete regional resection of the tumor may be the most effective treatment.