The present invention provides a polyvinyl alcohol-based resin composition having less coloration from melt processing and having high aging stability of the melt viscosity comprising a polyvinyl alcohol-based rein having a structural unit represented by the following formula (1) and having an absorbance of 0.1 to 0.3 of 280 nm in an ultraviolet absorbance spectrum as a 4 mass % aqueous solution, a carboxylic acid and an alkaline (earth) metal salt, wherein when an aqueous solution of the polyvinyl alcohol-based resin composition is prepared so as to have a content of the polyvinyl alcohol-based resin of 4 mass %, the pH of the aqueous solution at 20° C. is from 5.5 to 7: wherein R1, R2 and R3 independently represent a hydrogen atom or an organic group, X represents a single bond or a bonding chain, and R4, R5 and R6 independently represent a hydrogen atom or an organic group.