PROBLEM TO BE SOLVED: To provide an oral composition which contains stably both cetylpyridinium chloride and a certain benzaldehyde which brings about an AI-2 activity inhibitory effect.SOLUTION: The oral composition contains the following components (A), (B), and (C): (A) 0.001 mass% or more and 0.2 mass% or less of one or more benzaldehyde selected from a vanillin, ethyl vanillin, isovanillin, and methyl vanilline (B) 0.001 mass% or more and 0.1 mass% or less of cetylpyridinium chloride (C) one or more pH adjustor selected from organic acid, inorganic acid except phosphoric acid, and salts thereof further the composition contains 0.1 mass% or less of phosphoric acid or a salt thereof, or does not contain phosphoric acid or a salt thereof, and has a pH of 4 or more and 6 or less at 25°C.
