Three new ionone glucosides named corchoionosides A, B, and C were isolated from the leaves of Corhorus olitorius, commonly called "moroheiya" in Japanese, together with seven known compounds, an ionone glucoside (6S, 9R)-roseoside, a monoterpene glucoside betulalbuside A, two flavonol glucosides astragalin and isoquercitrin, two coumarin glucosides scopolin and cichoriine, and chlorogenic acid. The absolute stereostructures of corchoionosides A, B, and C were determined by chemical and physicochemical evidence, which included the result of application of a modified Mosher's method, the CD helicity rule, and chemical correlation with (6S, 9R)-roseoside. Corchoionosides A and B and (6S, 9R)-roseoside were found to inhibit the histamine release from rat peritoneal exudate cells induced by antigen-antibody reaction.