To prepare a dry coating film having largely improved water resistance, adhesiveness and lifting resistance, to obtain a water-based coating material which is a material for the dry coating film and has high storage stability, and to obtain a copolymer resin aqueous dispersion composition used for the water-based coating material.

The aqueous dispersion composition of the copolymer resin is characterized by comprising (A) the aqueous dispersion of the copolymer resin having a weight-average mol.wt. of 30,000 to 300,000 and (B) a silane coupling agent in a solid content amount of 0.05 to 10 wt.% based on the component (A).