To provide a water soluble adhesive for repairing a gypsum casting mold for manufacturing a tire mold which has good tackiness at room temperature, can maintain its tackiness even at 200C, and furthermore does not allow a splinter of the gypsum mold at the place to be repaired to come off even on pouring a molten metal having a temperature of higher than 700C.

The adhesive for repairing a gypsum casting mold which repairs a chipped portion of the gypsum casting mold for manufacturing a tire mold is an emulsion composed of an acrylic ester copolymer (X), a polyvinyl acetate (Y), and water (Z), and the weight mixing ratio thereof satisfies the relationship represented by formula (1): Y/X=0.1-0.3 and formula (2): (X+Y)/Z=1.0-1.2.