"Adrenomedullin (AM)" is a novel hypotensive peptide which was discovered in human pheochromocytoma by monitoring the elevating activity of platelet cAMP. In addition, a novel 20 residues hypotensive peptide, termed "proadrenomedullin N-terminal 20 peptide" (PAMP) is processed from proadrenomedullin. By RNA blot analysis, AM mRNA was found to be highly expressed in several tissues including ventricle, lung, kidney, aorta and vascular cultured cells as well as in adrenal medulla. Both AM and PAMP shows hypotensive effects in anesthetized rats, but exhibits different hypotensive mechanism. AM possesses multiple biological effects involving in cardiovascular homeostasis. Further, plasma AM as well as PAMP concentrations significantly increased in various cardiovascular diseases including hypertension and congestive heart failure. The present review summarizes the recent advancement of AM research and demonstrated that AM and PAMP are important vasoactive peptides involved in the physiology and pathophysiology of circulation control.