Urocotin (Ucn), originally isolated from rat mid-brain in 1995, is a member of corticotropin -releasing hormone (CRH)-related peptides. Ucn is widely distributed not only in central nervous system but also in peripheral organs. To date, a number of studies have revealed that Ucn has  various effects not only on the central nervous system but also on the pheripheral organs, especially on the cardiovascular system and the placenta. Ucn, as well as CRH. exerts its cardiovascular effects, such a positive inotropic actions, vasodilating actions and secretions of atrial natriuretic peptide and brain natriuretic peptide via the CHR type 2 receptor, which is dominantly expresssed in the heart. Recent findings on the studies of the Ucn actions in the cardiovascular system have revealed that  Ucn exerts cardioprotective actions in ischemic condition and that Ucn improves hemodynamic conditions in experimental cardiac failure. Based on these evidences, Ucn may play a certain pathophysiological roles in cardiac diseases.