OBJECTIVE： To study the hemostatic effect and mechanism of the polysaccharides from Bletilla striata in blood heat and hemorrhage （BBH） model rats. METHODS： Rats were randomly divided into normal control group， model group， Yunnan baiyao group （0.50 g/kg）， and BSP low-dose， medium-dose and high-dose groups （0.34，0.68， 1.35 g/kg）， with 10 rats in each group. Except for normal control group， those groups were given water decoction of Rhizoma Zingiberis and 5％ ethanol to induce BBH model. After modeling， those groups were given relevant medicine intragastrically， once a day， for 14 days， except normal control group and model group were given normal saline intragastrically. 1 h after last administration， body weight， food intake， water intake， the rate of platelet aggregation， the contents of t-PA and PAI-1， pathological change of lung and stomach were all detected in each group. RESULTS： Compared with normal control group， body weight， food intake， maximal rate of platelet aggregation and the content of PAI-1 were decreased in model group； while water intake， the content of t-PA and ratio of t-PA/PAI-1 were increased （P＜0.05 or P＜0.01）. Moreover， hemorrhage and inflammation of lung and stomach were found. Compared with model group， the body weight and food intake of Yunnan baiyao group， BSP low-dose， medium-dose and high-dose groups were increased， while water intake were decreased （P＜0.05 or P＜0.01）； the maximal rate of platelet aggregation and the content of PAI-1 were increased in Yunnan baiyao group， BSP medium-dose and high-dose groups， while ratio of t-PA/PAI-1 were decreased （P＜0.05 or P＜0.01）， the pathological changes of lung and stomach relieved to varying degrees. CONCLUSIONS： BSP exerts hemostatic effect by up-regulating the rate of platelet aggregation， rising fibrinolysis systems， improving the lesion of lung and stomach.