The present study was aimed to investigate the effect of Chrysanthemum morifolium Ramat. (CM) on isolated rat heart and ventricular myocytes during ischemia/anoxia and reperfusion/reoxygenation. The ischemia/reperfusion injury was induced by ligation the left artery descending coronary of isolated rat heart for 30 min followed by 30 min reperfusion with Langendorff equipment. Cell contraction in enzymatically isolated ventricular myocytes was determined by a video tracking system. The results showed CM (0.25 g/L to 1.0 g/L) increased left ventricular developed pressure (LVDP), +/- dp/dt(max), LVDP x HR and coronary flow (CF) and decreased heart rate (HR) in dose dependent manner. CM (0.5 g/L) attenuated the reduction of LVDP, +/- dp/dt(max) and CF caused by ischemia/reperfusion. CM (0.25 g/L to 1.0 g/L) increased peak velocity of cell shortening/relengthening (+/- dL/dt(max)) and contraction amplitude (dL) of isolated ventricular myocytes in a dose-dependent way under control condition, but without significant effect on end-diastolic cell length (L0). Under anoxia 5 min followed by 10 min reoxygenation, CM attenuated the reduction in contractile parameters. The results suggest that CM processes cardioprotective effect during ischemia/anoxia and reperfusion/reoxygenation in the isolated rat heart and the ventricular myocytes.