One or more aluminum compounds (a) selected among potassium aluminum sulfate, anhydrous potassium aluminum sulfate, and ammonium aluminum sulfate and sodium chloride (b) are incorporated into an oral composition, the amount of the ingredient (a) being 0.2-3 mass%. By the method of improving the astringency of an oral composition, an oral composition can be obtained which has a high astringent effect in the oral cavity at the time of use and retains therein the high astringent effect even after use. This oral composition does not have a metallic taste attributable to a polyvalent metal, and has excellent suitability for use and satisfactory safety.