This article deals with the mechanical properties of wood powder polypropylene composite panels and the morphology of the esterification of the wood surface while varying the level of wood content. Compared with 100% PP boards, the mechanical property results for the composite boards, except for impact strength, were observably improved with all wood powder contents. On the other hand, the morphology characteristics of the composites showed that the esterification treatment of the wood surface could improve the interfacial adhesion and dispersion between the polypropylene and wood powder. The SEM observation revealed that there were inlay structures in the composites, which meant that there also had been a physical combination between the polypropylene and wood powder.