The effects of T-2 toxin on the activities of B-type, L-type and T-type Ca²⁺ channels were recorded on cultured ventricular myocardiocytes of neonatal Wistar rats by cell-attached patch clamp technique. T-2 toxin at dose of 10 mg/L significantly inhibited the activities of the three types of Ca²⁺ channels. The open time of Ca²⁺ channels was shortened and the openstate probability was decreased, whereas there were no significant variations in the amplitude of ionic current flowing through the Ca²⁺ channels. Compared with verapamil and Bay K 8644, the effects of T-2 toxin on the Ca²⁺ channels were similar to the blockade effect of verapamil. It was suggested that the cytotoxic action of T-2 toxin may be due to the damages of cell membrane .