Abstract:The animal experiments showed that the effect of the Buyang Huanwu Decoction, such as prolongation of clolting time and inhihition of thrombosis in mice, became increased when Rhizonla Cyperi,Hirudo and Borneluom Syntheticum were added into the decoction, When doses of Hirudo,Rhizoma Cyperi and Bornelum Syntheticum were 1.5g, 3g and 0.15g respectively,the decoction exhibited maximal effects.