Leiomyosarcoma of stomach is a malignant tumor originating from the smooth muscle tissue of the stomach. It ranks second only to non-Hodgkin's lymphoma among non-epithelial malignant tumors of the stomach. Its clinical manifestations lack specificity in X-ray barium meal and gastroscopy, and it is easily confused with gastric cancer, gastric leiomyosarcoma and other primary gastric tumors. Preoperative diagnosis and differential diagnosis are difficult. Clinically, gastric leiomyosarcoma is not easy to be completely removed, and the chemotherapy effect is not good, so the patient's prognosis is poor. Gastric leiomyosarcoma mostly occurs from the gastric muscularis propria, which is relatively rare, accounting for only 20% of gastric tumors. There is little difference between genders, and the average age is 54 years old.