The short chain peptides derived from sardines were incubated for 120min with an extract of porcine small intestinal mucosa. Digestionresistant dipeptides found in the digest, Val-Tyr, Val-Trp, Ile-Tyr and Ile-Trp, inhibited angiotensin I converting enzyme (ACE). Amounts of the four dipeptides isolated from the digest using a Sep-pak C-18 cartridge column and three steps of high-performance liquid chromatography, were 85.88, 21.87, 10.69 and 6.51mg/100g peptides, respectively, and the contribution of four peptides to total ACE inhibitory activity was 10.5%. It was confirmed that ACE inhibitory dipeptides were present in the digest of the short chain peptides.