Aim To study the effect of TNFαon L-type cacium channel current (ICa-L) in isolated guinea pig ventricular myocytes in normal Tyrode solution and with imitating acute ischemia. Methods Using the whole cell patch clamp technique in isolated guonea pig ventricular myocates both normal Tyrode solution or simulation of acute ischemia. Results Under normal Tyrode solution, the application of TNFα (100 kU/L, 300 kU/L and 500 kU/L) did not produce any detectable alterations on peak of ICa-L, but inhibitory rate on peaks of ICa-L were decreased markedly by 46.5% ± 3.5% , 62.7%±3.0% and 80.7% ±3.7% respectivelyby TNFα at the same concentration accompany simulation of acute ischemia and showed dose-dependence; there are significant difference compare with control group or simulate of acute ischemia alone group ( P< 0.05, respectivelyby) . Conclusion TNFαrwould not alter peak of ICa-L in guinea pig ventricular cells under normal Tyrode solution; but increased inhibitory effects of ischemia on peaks of ICa-L accompany imitation of acute ischemia and showed concentration-dependence .