Urocortin (UCN) is a one of the potent emerging cardioprotector and vasodilator peptide released upon stress which is related to corticotrophin-releasing factor family (CRF). We examined Ucn effect in isolated heart subjected to ischemia/reperfusion and on vascular tone of rat coronary artery. We used langendorff system to study the heart hemodynamics parameters, Mulvany system to measure vessel contractility, and Ca²⁺ imaging system for intracelular Ca²⁺ study. We observed that Ucn provoke an increase of heart contractility, meanwhile it decreased the left ventricular pressure and the pressure of coronary perfusion. In coronary artery pre-contracted with phenylephrine (PE), Ucn induced a relaxation via a cAMP/PKA mechanism. We observed that SOCE modulated by Ca²⁺ independent phospholipase A2 (iPLA2) is involved in PE-induced coronary vasoconstriction. Furthermore, we found that Ucn inhibited iPLA2 activaty and blocked the SOCE induced by the emptying of the stores with thapsigargin in isolated smooth muscle cell. Our data shows that UCN affect heart performances and produced a vasodilatation by the modulation of iPLA2 and SOCE in rat coronary artery.