Abstract: Modification and preparation of Polyvinyl Acetate(PVAc) as mainly used as adhesive were very important. Urea was added in emulsion-polymerization of Vinvl Acetate (VAc) and N-Hydroxymethyl Acrylamide(NMA), and performances of the emulsion modified before and after were investigated. Results showed that water-resistance, bonding and solid content of PVAc-NMA-Urea were successfully improved. When the mass rate of urea to VAc was 1%～2%, average wet bond strength was 2.04 times than that of PVAc, and average solid content was also 17.85% higher than that of PVAc.