PURPOSE: To provide a melt coating resin which has a low melt viscosity and can provide a fusible layer when applied in a molten state to woodboard, by mixing a plasticier such as rosin (ester) or petroleum resin with a modified polyolefin, obtd. by copolymerizing a polar monomer, to form a uniform solution.

CONSTITUTION: 0.001W15wt% polar monome such as methyl acrylate or maleic acid is copolymerized with a polyolefin such as polyethylene or polypropylene to produce a modified polyolefin resin compatible with a plasticizer such as rosin. At least one plasticizer selected from among rosin (ester), petroleum resin, etc. is uniformly mixed with the modified polyolefin resin to obtain the desired melt coating resin. The resin is applied to the surface of a woodboard 1 to form a fusible layer composed of the resin and at the same time to fill grooves 4 such as vessels, cracks, flaws, etc. on the surface of the woodboard 1 with the resin to obtain a concrete form, a decorative sheet, etc.