Background and Objectives: Active oxygen species (ROS) are direct or indirect causes of cell damage. Continuously active heart muscle as an oxidative tissue is one of the tissues susceptible to oxidative damage. Malondialdehyde is one of the lipid peroxidation products, which is considered in the studies as an indicator of oxidative damage level. Crocin is also a carotenoid extracted from Saffron, which can affect the damage level with its antioxidant properties. In this study, the effect of crocin supplementation on the alteration of Malondialdehyde and CATALASE cardiomyocyte, was investigated in male rats poisoned with hydrogen peroxide. Methods: In this study, 32 male Wistar rats (mean weight, 180± 20g) were randomly divided into four groups including: control, sham (saline injections), hydrogen peroxide, and Crocin and Hydrogen peroxide. For induction of oxidative stress in the H2O2 groups, 1mmol/kg H2O2, was injected to the rats intraperitoneally every other days for 3 weeks, and in the supplement group, the rats intraperitoneally received 12. 5mg/kg of crocin, every days. The alteration of MDA and CAT, was performed by ELISA technique. Data analysis was performed using one way ANOVA and Scheffe test. Results: In this study, induction of H2O2 caused a significant increase in malondialdehyde and a significant decrease in the activity of CATALASE enzyme, and crocin consumption led to a significant reduction in malondialdehyde and significant increase in the activity of CATALASE enzyme in the heart tissue (p<0. 01). Conclusion: The results of this study showed that supplementation with crocin leads to strengthening of antioxidant system and reduction of oxidative stress damages.