Disclosed is a peptide having an inhibitory activity on an ACE (an angiotensin-converting enzyme) (i.e., an anti-hypertensive activity)/a blood vessel-protecting activity. Also disclosed is a functional food or a medicinal agent comprising the peptide. The peptide comprises an amino acid sequence depicted in any one of SEQ ID NOs: 1 to 23. The peptide has an anti-hypertensive activity and/or a blood vessel-protecting activity. The functional food or the medicinal agent comprises the peptide as an active ingredient, and can be ingested on a daily basis to meliorate hypertension or exhibit its blood vessel-protecting effect including the recovery of a disorder in an endothelium and the maintenance of the functions of an endothelium.
