To provide a method for producing an aqueous resin dispersion excellent in stability, even upon a large scale production, without viscosity increase in an emulsion and generation of a large amount of aggregates etc. when producing a polymer having a large amount of carboxyl groups useful for an alkali-soluble thickener etc. by emulsion polymerization.

A preemulsion is prepared by adding a liquid monomer mixture prepared in advance in an another container to an emulsifier aqueous solution and stirring the resulting material, and emulsion polymerization is carried out. Preferably, a preemulsion-preparing process and/or an emulsifier aqueous solution-preparing process is carried out within a temperature range of polymerization starting temperature±20°C.