Abstract: The effects of Xinchuanling (XC-1)and its derivative,XC-2(8204), on the cardiohemodynamics were examined in 16 anesthetized open chest dogs. XC-1 was administered repeatedly by vein at 5 minutes intervals at the doses of 0.5, 1.0, 2.0 and 4.0mg/kg. The MAP, LVSP,±LV dpdt_max, HR and TPR decreased, the CI and SI increased while no significant changes in LVP, CVP, ±LV dp/dt/p and MVO₂ were observed. The blood flow of the left circumflex coronary, internal carotid and femoral artery increased transiently and the vascular resistance of these arteries decreased. The cardiohemodynamics induced by successive doses of XC-2 (0.5,1.0,2.0 and 4.0 mg/kg) were similar to those seen with XC-1. Intravenous injection of XC-2(5mg/kg) produced similar but milder effects as compared with the effects of Successive dosing. The effects of the two compounds on cardiovascular system may be due to direct relaxation of the vessels and blocking of the a and β adrenoceptors.