To prepare a coating liquid having excellent adhesiveness to a substrate such as a metal, a plastic, glass, ceramics, wood, cement, mortar or brick, imparting corrosion and scuff resistances and further characteristics such as abrasion resistance, stain resistance over a long period, wettability by abrading water, sealability, chemical and oxidation resistances, physical barrier effects, heat and fire resistances or antistatic properties to the substrate after coating and having film-forming properties.

This coating liquid comprises a solvent solution containing 0.1-35wt.% of a solvent-soluble inorganic or organic polysilazane containing a repeating unit represented by the formula and a catalyst such as 4,4'-trimethylenebis(1-methylpiperidine) in an amount of 0.1-10wt.% based on the inorganic polysilazane purity content in a solvent.