NOVELTY - Preparation of a composition (I) comprises: hydrolyzing a titanium compound with water and adding alcohol and acid in it, followed by hydrothermal synthesis to grow crystals; mixing the titanium compound and an organic solvent with water and raising temperature, and adding acid in it; mixing each compound prepared by hydrothermal synthesis and aqueous synthesis to give photocatalyst sol; synthesizing a water soluble silicate binder compound by hydrolyzing silicate compound with excessive water; and mixing the photocatalyst sol, the water soluble binder compound and alcohol altogether.    USE - (I) is useful for protecting solar cell module (claimed). (I) is useful as coating composition.    ADVANTAGE - (I) has excellent weatherability and durability. The low iron transparent glass made by (I), has excellent transmittance and durability with the compound to increase maximum power generation of module and light transmittance, compared with conventional low iron glass. The photocatalyst and water soluble binder provide excellent photoactivity, stability and dispersing power in addition to the excellent coating capacity and organism disposing capacity. The solar cell module coated by (I), has excellent durability and weatherability even after long-term use.    DETAILED DESCRIPTION - Preparation of a composition (I) for protecting solar cell module, comprises: hydrolyzing a titanium compound with water and adding alcohol and acid in it, followed by hydrothermal synthesis to grow crystals; mixing the titanium compound and an organic solvent with water and raising temperature, and adding acid in it, followed by aqueous synthesis to improve dispersibility; mixing each compound prepared by the above hydrothermal synthesis and aqueous synthesis to give photocatalyst sol; synthesizing a water soluble silicate binder compound by hydrolyzing silicate compound with excessive water; and mixing the photocatalyst sol, the water soluble binder compound and alcohol altogether.