AIM To study toxicity and mechanism of SOV on ventricular myocardial cells. METHODS Cyclical perfusion was used to acutely detach the mature guinea pig myocytes into single cells. The CK,LDH activity in a medium of myocardial cells was measured for 30,60,120 and 180 min after the effect of SOV at 1,10, 100 ?mol?L -1 and 1 mmol?L -1 . Rates of cell viability and apoptosis were also measured. The protein content and Na +,K + ATP enzyme activity of the myocardial cells were measured as well. An electron microscope was used to investigate cell nucleus and organelle morphology. RESULTS The release of CK, LDH and protein from the myocardial cell gradually increased after administering SOV at 100 ?mol?L -1 and 1 mmol?L -1 to the cells. While ,the cell activity decreased. CK release, which indicated the extent of myocardial cell injury, was more sensitively than that of LDH and cell viability. Meanwhile ,the activity of Na +,K + ATP enzyme decreased gradually. The rate of apoptosis of myocardial cells significantly changed for 180 min after treated with SOV at 100 ?mol?L -1 and 1 mmol?L -1 . CONCLUSION Guinea pig ventricular myocardial cells were only injured when exposed for 30 min to 100 ?mol?L -1 and 1 mmol?L -1 concentrations of SOV higher than the effective concentration of the drug.