The present invention provides a water-dispersant resin composition for perforating a printed wiring board excellent in preciseness of the processing position and plating throwing power when perforating, a sheet for perforating using the composition, a process for perforating a printed wiring board using the sheet. More specifically, the present invention provides a water-dispersant resin composition for perforating a printed wiring board comprising a water-soluble polymer (A) and a polymer compound (B) containing the compound represented by the following formula (1) as a copolymer component, a sheet for perforating using the composition, and a process for perforating a printed wiring board using the sheet. ##STR1##

(wherein, R represents hydrogen or a methyl group, and n represents an integer of 10 to 22).