To provide: an aqueous liquid which can give excellent antistatic properties, simultaneously excellent blocking resistance, transparency, stainproof, and solvent resistance to a thermoplastic polymer film; a surface layer forming method using such aqueous liquid; and a modified thermoplastic film which has simultaneously outstanding performance.

The aqueous liquid includes, as an aqueous liquid applied to the surface of a thermoplastic polymer film: a specific organopolysiloxane resin aqueous liquid; a specific antistatic agent aqueous liquid; and a specific resin binder aqueous liquid. The surface layer forming method uses the aqueous liquid. The modified thermoplastic film is obtained by the surface layer forming method.