Abstract: Objective: To analyze the clinical and pathologic features of the gastrointestinal stromal tumor(GIST).Methods: The clinical and pathological data of 53 patients of GIST were retrospectively analyzed.The expressions of CD117,CD34,vimentin,smooth muscle actin(SMA) and S-100 protein were detected with immunohistochemical staining.Results: The GIST was rarely seen;the stomach and the small intestine were its predilection sites;the size of the tumor was significantly correlated with the degree of malignancy(P<0.01).There was no correlation between malignancy and sex or age(P>0.05).The expressions rates of CD117,CD34,vimentin,SMA and S-100 protein were 84.91%,67.92%,94.34%,13.21% and 60.38%,respectively.Forty-four patients underwent radical excision,9 patients palliation excision and 11 patients were followed up.The post-operation live time was 7 to 33 months.Conclusions: The diagnosis of GIST is difficult,for it lacks clinical features.Final diagnosis still relies on pathological examination.The expressions of CD117 and CD34 protein are important predicting markers for final diagnosis of GIST.