Organ-montmorillonite(OMMT) modified rosin emulsion was prepared by inversion process.The structure of OMMT and rosin emulsion was studied by using XRD and TGA.The effects of rosin emulsion on the water resistance and mechanical properties of waste paper fibers were also studied.The results show that the water resistance,and mechanical properties of waste paper fibers are also improved obviously by adding OMMT modified rosin emulsion.