The incorporation of polymers derived from renewable resources is more desirable in the preparation of wood composites due to its sustainability. As biomass feedstock, rosin has been used for the preparation of wood-based composite material. However, the high leachability and non-reactive with wood limit its application. Three kinds of rosin derivatives synthesized with reactive groups in the current study were confirmed by 13C NMR and Fourier transform infrared spectroscopy. The polymerization process and polymer properties of the derivatives were studied by the differential scanning calorimetry and gel permeation chromatography. The poplar wood was impregnated by rosin derivatives solution and then oven heated to induce in situ polymerization. The results indicated that the derivatives could penetrate into wood structures, polymerize in both wood cell walls and lumina, and efficiently improve the physical properties and surface hardness of wood. Moreover, the extraction indicated that rosin derivatives could permanently bulk wood structure through the formation of polymers. Our studies provide a new approach to modify fast-growing wood using renewable resources.