PURPOSE: To obtain a base for a hair grooming agent by polymerizing a combination of a polyethylene glycol (meth)acrylic monoester, siloxy group-bearing (meth)acrylic acid and (meth)acrylic ester and/or (meth)acrylamide.

CONSTITUTION: The base for a hair grooming agent can be obtained by polymerization between (A) a monomer of formula I (R1 is H or methyl; R2 is H, alkyl or phenyl; n is 2-23) (e.g. methoxytetraethylene glycol, 20-80wt.%), (B) a monomer of formula II [e.g. acryloyloxypropyltris(trimethylsiloxy)silane, 1-20wt.%] and (C) a monomer of formula III (R3 is 1-4C alkoxy or amide) (e.g. methyl acrylate, 5-60wt.%), and pref. (D) ≤30wt.% of a copolymerizable ethylenic unsaturated monomer (e.g. (meth)acrylic acid, styrene, vinyl acetate). This base has the following advantages: (1) excellent in adhesion to the hair, (2) imparting the hair with excellent luster and smooth touch, and (3) having good set retentivity.