Abstract: The composite emulsion of modified waterborne polyurethane(WPU)was prepared by copolymerization using the isobornyl methacrylate(IBOMA)which was the derivative of the renewable resource turpentine as the modifying reagent. Influence of R value, the contents of 2,2-dimethylolpropionic acid(DMPA)and diethylene glycol(DEG), the neutralization degree of the composite, and the reaction time of the emulsion on the viscosity, stability of the composite emulsion, water absorption and the tensile strength of the modified WPU film was studied. The suitable modification conditions were determined as follows: the amount of IBOMA 30%, R value was 1.70, DMPA 4.0%, DEG 0.5%, neutralization degree 100%, and reaction time 6 h. The comprehensive properties of WPU before and after modification were enhanced, the water absorption was reduced from 11.53% to 3.91%, the glass transition temperature Tg was increased from -7.23 to 25.31℃, and the tensile strength was increased from 23.42 to 55.18 MPa, respectively. Furthermore, the modified WPU composite was analyzed by FT-IR and DSC.