An object of the present invention is to provide a new acetoacetic ester group-containing polyvinyl alcohol-based resin that contains less amount of water-insoluble matter and is excellent in transparency and viscosity stability when converted into an aqueous solution, and that realizes excellent water resistance by combined use of a crosslinking agent. The invention provides an acetoacetic ester group-containing polyvinyl alcohol-based resin containing a structural unit represented by the general formula (1): wherein at least one of R1 and R2 represents an acetoacetyl group, R3, R4, R5, R6, R7 and R8 each independently represents an arbitrary substituent, and X represents a single bond or an arbitrary bonding chain.