Urocortin(UCN),a member of the corticotropin-releasing hormone(CRH)-related peptides,has been reported to play biologically diverse roles in several systems such as cardiovascular, reproductive, appetite, stress, inflammatory responses, etc. In heart, it was reported to have protective effects.On the other hand,it was also reported to have cardiac inotropic and hypertrophic effects and hence to cause cardiac remodeling.This paper will review the effects of UCN in cardiac system.