Objective To explore the impact of blood-activatingand qi-nourishing therapy on the hypercoagulable state of rats after femur fracture.Methods One hundred and twenty SD rats were randomly divided into 4 groups,namely normal group,model group,low-molecular-weight heparin(LMWH) group,combination group (LMWH + Tongmai Decoction),30 rats in each group.The rat model of femur fracture was established.After successful modeling,LMWH group was given subcutaneous injection of LMWH 600 U/kg,and the combination group was given subcutaneous injection of LMWH 600 U/kg together with gastric gavage of Tongmai Decoction,the model group was given subcutaneous injection of the same volume of normal saline.The treatment lasted for 1-7 days after the surgery.The pathologic features of the left great saphenous vein were observed by HE staining method,and the relative volume,thickness and quantity of the blood vessels were also measured.The plasma D-dimer (D-D) and fibrinogen (FIB) levels were determined by biochemical analyzer,and the plasma levels of whole blood viscosity at low shear rate (WBV-lsr) and whole blood viscosity at high shear rate (WBV-hsr) were measured with hemodynamic detector.Results On day 7 after the modeling,less endothelium cells,agglomerative red cells,and large thrombi were found in the great saphenous vein tissue section of the model group under microscope.Compared with the normal group,the levels of D-D,FIB,WBV-lsr and WBV-hsr in the model group at various time points were increased,the difference being significant (P ＜ 0.05).After 7-day treatment,the levels of D-D,FIB,WBV-lsr and WBV-hsr in LMWH group and combination group were lower than those of the odel group,and the decrease in the combination group was superior to LMWH group(P ＜ 0.05).The blood vessel endothelium cells in the combination group were arranged neatly with same cellular width while without enlargement or swelling,the effect being superior to that of LMWH group.Conclusion Blood-activating and Qi-nourishing therapy can effectively relieve hypercoagulable state of rats after femur fracture.