Abstract: Liensinine(Lien), an alkaloid extracted from the green seed embryo of Nelumbo nucifera Gaertn, has been shown to have anti-arrhythmic action, its mechanism may be related toblockade of Ca²⁺,Na⁺ influx. Lien 3 mg/kg iv may temporarily inhibit all parameters of haemo-dynamics in anesthetized or pithed rats. The inhibitory effects on LVP, +dp/dt_max, and SAP in anes-thetized rats are slightly stronger than those of quinidine(Oui) 3 mg/kg. Lien 1～30 mg/kg dose-de-pendently produced these actions. Lien and Qui 12 mg/kg lowered LVP, +dp/dt_max, and SAP by33%, 37%, 29% and 9%, 12%, 9% respectively. While both of them inhibited the other param-eters of haemodynamics with nearly equal degrees. The degrees of inhibitory effect of Lien 12 mg/kgon all haemodynamic parameters nearly corresponded to these of verapamil 1 mg/kg. Lien 1～100μmol/L reduced the contractile force of isolated left atria and the spontaneously beating rate of isolatedright atria of rabbits in concentration-dependent manner. Thes esults indicate that the properties of the effect of Lien on haemodynamics may be similar to those of verapamil and different from those ofQui.