Provided is an oral composition having high perioral disease-preventing effect by removing, for a long period of time, active oxygen in cells constituting gingiva. An oral composition containing: (A) a lactam compound and/or a salt thereof having an acidic group selected from the group consisting of pyrrolidone carboxylic acid, 6-oxo-2-piperidine carboxylic acid, and 3-(2-oxo-1-azepanyl) propanoic acid； and (B) an antioxidant.
