A water-based composition with excellent anticorrosion effect is provided. A water-based composition comprises: compounds or salts thereof or their solvent complexes shown in the following general formula (1) [where X represents halogen atoms]； and quaternary ammonium type surfactants.提供具有優異的防腐效果的水性組合物。一種水性組合物，含有：下述通式(1)[式中，X表示鹵原子]所示的化合物或其鹽或者它們的溶劑合物；和季銨型表面活性劑。
