Abstract: A conventional polyurethane-acrylate(PUA) with carboxyl as pendant group was prepared from dimethylolpropionic acid, polyethylene glycol, tolylene-2,4-diisocyanate and hydroxyethyl methacrylate. A modified PUA(g-PUA) with carboxyl group was obtained by grafting the PUA onto the copolymer of glycidyl methacrylate and methyl methacrylate through the reaction between the glycidyl and part of the carboxyl groups. The PUA and g-PUA could be easily dispersed in water in the form of self-emulsified latex after neutralization by triethylamine. The interfacial tension of the acquired dispersions was lower than that of deionized water. The investigation of photocuring on differential photocalorimeter showed that the g-PUA could polymerize to a greater extent than the conventional PUA. The glass transition termperature, thermal stability and physical properties of the cured films from the conventional PUA and the g PUA dispersions were measured. The effects of molecular weight of polyethylene glycol used on the above properties were also investigated.