Composite microemulsion of anionic polyurethane acrylate polymerizable emulsifier (APUA) and MMA was polymerized with AIBN and K2S2O8 as initiator respectively

and the nanometer core-shell latex particle was synthesized．In the latex particles polyurethane is as the shell of the latex particles and PMMA as the core．Effects of APUA content and polymerization temperature on polymerization kinetics were studied．Influences of different initiators and emulsifier concentration on morphology and size of latex particles were observed by TEM. The results suggest that stable core-shell P(MMA-UA) nanometer latex particle can be synthesized by polymerizable emulsifier APUA

and the particle size is about 50 nm；with increasing APUA emulsifier content

size of latex particles decrease. Effects of different kind of initiators on properties of latex were significant．When APUA was used as emulsifier and K2S2O8 as initiator

hydrogel of P(MMA-UA)may appear during polymerization or storing．