It is an object of the present invention to provide an antifouling coating resin dispersion which has excellent storage stability and water resistance in sea water, can exhibit an antifouling effect over a long period of time, and has self-polishing properties with excellent adhesiveness. A method for producing the antifouling coating resin dispersion according to the present invention includes the steps of: producing a polymer (A) containing a divalent metal； and dispersing the polymer (A) in a dispersion medium containing water or a mixture of water and an organic solvent. The polymer (A) containing a divalent metal is obtained by subjecting 1 to 40% by mass of a divalent-metal-containing ethylenically unsaturated monomer (a1), 0 to 8% by mass of a carboxyl-group-containing ethylenically unsaturated monomer (a2), 0 to 40% by mass of a hydroxyl-group-containing ethylenically unsaturated monomer (a3), and 99 to 22% by mass of another ethylenically unsaturated monomer (a4) to solution polymerization in a multi-stage which includes two or more stages.
