Abstract: Objective 　To investigate clinicopathologic and immunohistochemical features and prognosis-related factors in gast rointestinal st romal tumors. Methods 　One hundred and three patients with gastrointestinal stromal tumors were studied. Pathomorphology in these patients were analysed after surgical operations. GSITs were divided into Benign and malignant tumor according to tumor size, mitosis and atypism. Immunohistochemistry was performed by the streptavidin peroxidase conjugaed method using a monoclonal antibody specifically against CD117 and CD34. Results 　Immunohistochemical expressions of CD34 and CD117 protein were detected in 90. 3 %(93/ 103) and 70. 0 %(69/ 103) patients, respectively.There were not significant differences among different sites of digestive t ract ( P > 0. 05) . 32year free-diseased survival in patients with benign tumors was significantly higher than those with malignant tumors (Ρ< 0. 05) . Conclusion 　CD117 and CD34 tumor marker may help to diagnose gastrointestinal stromal tumors. Pathomorphological features on the basis of tumor size, mitosis and atypism can provide useful information for the prognosis of GST patients.