Rosin is a natural product, it has a good hyd-rophobic c-haracter, and is human-friendly. In this study, Styrax tonkinensis (Pierre) wood was impregnated to the mixtures of 1%, 2%, 4% rosin sizing agent and 3% copper sufrate before being coated by Polyurethane (PU), while the effects ofrosin sizing - copper sulfate treatment on some surface c-haracteristics such as changes in color, glossiness, and adhesion of coating film on the treated wood surface were also studied. The results showed that combinations of rosin sizing agent and copper sulfate to impregnate for styrax wood did not influence the penetration of the preservative complexes into the wood. However, the surface of wood treated with rosin sizing - copper sulfate has become slightly darker but it has no negative effect on the color and gloss of coating film on the treated wood surface. Moreover, wood after being preserved by rosin sizing - copper sulfate solutions could improve the adhesion of coating film on the surface of treated wood. When the concentration of rosin increases the adhesion tends to slight decrease, however, it does not affect the changes in color and gloss of the coating film.