Abstract: A water-proof wood board having plastic paste between a core board and surface sheets to combine the core board and the surface sheets together. The plastic paste comprises polyvinyl chloride resin, the plastic paste being placed on top surface and bottom surfaces of the core board and penetrating into the wood grain of the core board and the surface sheets. The surface sheets are placed on at least two sides of the core board with the adhesive provided by the plastic paste. The plastic paste fills in between the core board and the surface sheets and penetrates into the wood grain of the core board and the surface sheets, which completely isolates the core board the wood board. Furthermore, plastic paste provides water-proof ability and insect-proof ability for the wood board.