OBJECTIVE：To investigate the effe cts of Buyang huanwu decoction on hemorheology and platelet related biological indexes of hyperlipidemia model rats. METHODS ：Male Wistar rats were randomly divided into blank control group （10 rats）and model group （40 rats）. Blank control group was given normal diet ，and model group was given high-lipid diet for 6 weeks at least to induce hypelipidemia model. After modeling ，rats were randomly divided into model control group ，positive control group （simvastatin，0.004 g/kg），Buyang huanwu decoction low-dose and medium-dose groups （3.5，14.0 g/kg，by crude drug），with 10 rats in each group. Blank control group and model control group were given normal saline intragastrically ， administration groups were given relevant drug intragastrically ，0.01 mL/g，once a day ，for consecutive 4 weeks. Thirty min after last medication ，hemorheological indexes （whole blood viscosity ，plasma viscosity ），platelet adhesion related indexes [adhesion rate，von Willebrand factor （vWF），fibronectin（FN）]，platelet release related indexes [ β-thromboglobulin（β-TG），platelet factor 4 （PF4）] and platelet fibrinolytic system related indexes [tissue plasminogen activator （t-PA），plasminogen activator inhibitor （PAI-1）]，platelet parameters （PLT，PDW，MPV，PCT，PLCR），4 kinds of coagulation parameters （APTT，TT，PT，FIB）were detected. RESULTS ：Compared with blank control group ，the whole blood viscosity （low，medium and high shear rate ），plasma viscosity，platelet adhesion rate ，the contents or levels of vWF ，FN，β-TG，PAI-1，PLT，MPV，PCT，PLCR and FIB in model control group were increased significantly （P＜0.05 or P＜0.01），and t-PA content was significantly decreased （P＜0.05）. Compared with model control group ，the whole blood viscosity （except for whole blood viscosity of high shear rate in Buyang huanwu decoction high-dose group ），plasma viscosity ，platelet adhesion rate ，the contents or levels of vWF ，FN，β-TG，PAI-1， PLT，PDW（except for Buyang huanwu decoction low-dose and high-dose groups ），MPV，PCT，PLCR（except for Byang huanwu decoction low-dose group ）and FIB were decreased significantly （P＜0.05 or P＜0.01），while t-PA content （except for positive control group ） was increased significantly （P＜0.05）. CONCLUSIONS ：Buyang huanwu decoction can significantly improve the pathological state in hyperlipidemia model rats by reducing blood viscosity and FN content ，improving platelet adhesion，enhancing fibrinolytic activity ，improving platelet aggregation ，inhibiting hypercoagulability and hyperplatelet release.