Abstract: The process of Wood Plastic Combination (PWC) is discussed in the paper. Timber is injected with polyvinyl element with positive and negative bases of styrene and maeic anhydride mixed with equimolar ratio and PWC is made through proper heating, reacting, heat releasing and self-polymerizing. The mechanical properties and dimensional stability of PWC are significantly improved in comparison with that of plain timber. It is indeed a good method for timber modification and improvement of wood quality for fast-growing species.