Objective To investigate the changes of the peripheral blood platelet counting and function the mouse model of idiopathic thrombocytopenic purpura (ITP) and to observe the effect of Zidian Granule (ZG). Methods The peripheral platelet counting was conducted with the automatic hemocyte analyzer; CD41 andCD61 level was measured with flow cytometry. Results The amount of the peripheral blood platelet in ITP model mouse was decreased after injection of antiplatelet serum (APS) and CD41 and CD61 were also decreased.(P