In order to provide experimental fundament and theory for clinical administration, the efficacy studies of buflomedil in vitro and vivo were conducted by using rabitt's chest artery strip and rabitts acute microcirculatory disturbance model reproducted with high molecular dextran, in which peripheral vascular dilating agent tolarzoline was acted as control agent. Experimental results showed that buflomedil of 6 ? 10-5~ 6? 10-4 mol?L-1 could inhibit con-tractions of rabbit artery strip induced by NA producing concentration-dependent, and get the curves of dose-activity shift towards right, which suggests buflomedil significantly dilates microvessels and increases blood flow velocity and capillary perfusion capacity per area (P