Blood pressure is regulated by many physiological systems in human. As for the vasopressor system, the renin-angiotensin system is thought to play an important role, where angiotensin II which is produced from the cleavage of angiotensin I by angiotensin I-converting enzyme has a potent vasoconstrictive effect. In this review, a number of bioactive peptides with antihypertensive potencies derived from natural proteins are reviewed. In addition, metabolism of bioactive peptides will be discussed.