The present invention provides an anti-hypertensive agent. The anti-hypertensive agent of the present invention contains, as an active ingredient, at least one peptide selected from the group consisting of peptides originally derived from globin proteolysate, each of which consists of one of the following amino acid sequences (1) to (6), or a globin proteolysate containing at least one of the peptides: (1) Val-Val-Tyr-Pro (SEQ ID: NO. 1); (2) Trp-Gly-Lys-Val-Asn (SEQ ID: NO. 2); (3) Trp-Gly-Lys-Val (SEQ ID: NO. 3); (4) Trp-Gly-Lys (SEQ ID: NO. 4); (5) Ala-Ala-Trp-Gly-Lys (SEQ ID: NO. 5); and (6) Phe-Glu-Ser (SEQ ID: NO. 6).