Seventeen wild vegetables consumed commonly in Korea were tested for inhibitory activities against alpha-glucosidase, followed by Bupleurum longeradiatum and Angelica decursiva. The hexane-soluble fractions of Hosta longipes, Ainsliaea acerifolia, Pedicularis resupinata, Bupleurum longeradiatum, and Angelica decursiva all at the concentration of 5 mg/ml, inhibited enzyme activity by greater than 50%, and the ethylacetate-soluble fractions of Hosta longipes, and Codonopsis lanceolata, and Bupleurum longeradiatum had relatively strong inhibitory activity against the enzyme. These results suggest that some edible plants merit further evaluation for clinical usefulness as anti-diabetic drugs.