The acute blood stasis rat model was made by injecting norepinephrine, then rats stayed in ice water bath for 4 mins. Whole blood viscosity (WBV), erythrocyte sedimentation rate(ESR), coagulation parameters, 6-keto prostaglandin F1α (6-KETO-PGF1α), thromboxane B₂ (TXB₂), endothelial nitric oxide synthase (eNOS) and endothelin-1 (ET-1) were measured. Results: Model group significantly up WBV and ESR level, APTT, PT, TT were decreased whereas FIB content was increased very significantly in rats of the model group, meanwhile the 6-keto-PGF1α and eNOS level were lower and TXB₂ and ET-1 level were higher. Lemon juice powder groups might down WBV and ESR level, extend PT, increase 6-keto-PGF1α level and decrease TXB₂ level, maintain the balance between 6-keto-PGF1α and TXB₂, whereas the eNOS level was higher and ET-1 level was lower than model group. Lemon juice powder has antithrombotic effect.