[Problem] To provide a hydrophilization treatment agent for aluminum-containing metal materials for forming a film capable of imparting excellent and lasting hydrophilicity and odor properties to aluminum-containing metal materials used in heat exchangers and the like. [Solution] A hydrophilization treatment agent for aluminum-containing metal materials including organic-inorganic composite particles, obtained by compounding a water-soluble resin (A) having a hydroxyl group, sparingly water-soluble inorganic oxide (B), organoalkoxysilane (C), and surfactant (D) in a specific ratio, and water, the organic-inorganic composite particles being 40-100 mass% on the basis of the total solids fraction mass.
