Renewable products have received much attention. Maleic rosin (MR) was reacted with hydroxyethyl methacrylate (HEMA) to form a macromonomer (MRH) containing double bond which could polymerize with styrene (St) or methyl methacrylate (MMA) through radical polymerization in the toluene. The copolymers MRH-St and MRH-MMA were characterized with infrared spectroscopy (IR), thermogravimetric analysis (TGA) and nuclear magnetic hydrogen resonance (1HNMR). The results showed that both of the copolymers were prepared successfully. As the increase of MRH content in the copolymer, the thermal stability of the copolymer was increased, in additional, it become dissolved in the toluene but swelled in it when more level of the MRH was incorporated.