Objective To study the anti-arrhythmia effect of crocetin and corresponding mechanism.Methods Animals (rats or guinea pigs) were randomly and equally divided into five groups:saline control group,positive drug control group,low-dose,medium-dose and high-dose crocetin group.Animals were anesthetized with urethane (1.2g/kg),then followed by the perfusion of aconitine (10?g/mL) through caudal vein in rats,or of ouabain (9?g/mL) through external jugular vain in guinea pigs in a constant velocity of 0.1mL/min,and the emergence time of ventricular fibrillation (VF),ventricular extrasystole (VE),ventricular tachycanlia (VT) and cardiac arrest (CA) were then detected and recorded.The recorded time was then translated to the cumulated amount of aconitine and ouabain.Experimental arrhythmia was induced by rapid injection of 4% CaCl2 (140mg/kg),and the emergence time,persistence time,incidence and death of arrhythmia after the administration were observed.Results Compared with the animals in saline control group,obvious anti-arrhythmia effects of crocetin were observed in those animals in each of crocetin groups (P