Rosae fructus is a traditional Chinese crude drug, used for purgative purposes. It is included in the Japanese Pharmacopoeia XV, in which its origin is stated to be Rosa multiflora Thunberg. These days, some imported Rosae fructus are on the market and the pharmacological activity of the imported product is in question. The chemical constituents of Japanese Pharmacopoeial Rosae fructus, imported from the People's Republic of China and whose plant origin is expected to be Rosa aff. multiflora, were investigated to give 2-hydroxynaringin 5-O-beta-D-glucopyranoside and L(S)-pyroglutaminic acid derivative as new compounds. However, although we made every effort, the major flavonoids in R. multiflora, multiflorins A and B, and multinoside A acetate, could not be isolated.