Abstract: The present study indicates that iv tetrandrine may transiently decrease bloodpressure ,while other hemedynamic parameters such as LVP,±dp/dt_max,LVEDP, HR and CO maynot be significantly altered. During coronary occlusion three of five dogs developed ventricular fibrillation (VF)and died inthe control group,i.e incidences of VF and mortality were 60%, While tetrandrine(Tet)appeared toreduce the severity of ischemic injury.It may alleviate arrhythmia and prevent VF and death in fourof the five dogsalso attenuated Ca²⁺ accumulation in myocardial cell ,reduced melondialdehyde(MDA)production in ischemic myocardial and decreased CPK release in comparison with the control.It appears that Tet may have significant protective effects against ischemia induced cardiacdamage in anesthetized dogs.