Objective　To study the clinical features, diagnosis and treatment of small intestinal stromal tumor (SIST). Methods　Clinical data of 45 SIST patients admitted to our hospital from July 2007 to December 2013 were analyzed retrospectively. The diagnosis was confirmed pathologically in all the patients. Results　The clinical manifestations of SIST were non-specific, and the most common manifestations were as follows: gastrointestinal bleeding in 29 patients (64.4 %), abdominal pain in 15 (33.3%) and abdominal mass in 4 (8.9%). The most common predilection sites of SIST were jejunum (n=21, 46.7%), duodenum (n=13, 28.9%) and ileum (n=9, 20.0%). The tumor was located at the jejunoileal junction in 2 patients (4.4%). The diagnostic rate of SIST by spiral CT was 73.7% (28/38), and it was the most accurate among all the examinations. Surgical operation was the most effective therapeutic method for SIST. All the 45 patients received surgical treatment, and according to Fletcher's criteria, there were 6 patients (13.3%) at very low-risk, 16 (35.6%) at low-risk, 8 (17.8%) at moderate-risk and 15 (33.3%) at highrisk of SIST. The postoperative immunohistochemistry showed that the positive rate of CD117 was 100%, while the positive rate of CD34 was 67.0% (30/45). Imatinib mesylate was helpful for patients who had palliative operation and for preventing postoperative recurrence. Reoperation could prolong the survival of patients who had a local recurrence or distant metastasis. Conclusions　 Clinical manifestations of SIST are non-specific, and its early diagnosis is difficult. However, spiral CT has a high diagnostic value for SIST. The surgical operation is the main method for treatment of SIST, and long-time oral imatinib mesylate medication after surgery can attain a better result for a long duration. DOI: 10.11855/j.issn.0577-7402.2014.07.11