The aim of this study was to explore the mechanism of domestic beta-aescin treating chronic venous insufficiency through observing its actions on the isolated canine saphenous venous tension, venous pressure, venous return and lymphatic return. The isolated canine spiral saphenous venous tension test was performed to detect the activity of the beta-aescin. Furthermore, in the condition of constant canine femoral artery perfusion kept in the extracorporeal circulation, we measured the changes of the canine femoral artery pressure, femoral artery flow and the lymphatic return flow after intravenous injection of the agent. The results showed that when beta-aescin was administrated at the dose between 5.0 x 10(-5)-5.25 x 10(-4) mol/L, it increased obviously the contractile tension of the venous to norepinephrine in a dose-dependent manner. With canine femoral artery perfusion kept constant, beta-aescin, whose doses were 50 mg and 100 mg, reinforced intently the canine femoral venous tension accelerated the rise of the venous pressure. These finding suggested that domestic betabeta-aescin extracted from Chinese Buckeye Seed had an effect on chronic venous insufficiency by strengthening the venous tension, increasing the venous pressure and promoting venous return and lymphatic return.