3-Allyloxy-2-hydroxyl-propanesulfonic (AHPS) salt was synthesized and used as a hydrophilic comonomer for the methyl methacrylate (MMA) and n-butyl acrylate (BA) emulsifier-free emulsion copolymerization system to obtain latices of stable and high-solid content. Properties of the latices, such as flow behavior, stability, and final diameter of the latex particles were studied. In addition, physical properties of the obtained copolymers, such as glass transition temperature (T-g), stress-strain behavior, and water resistance were investigated. With the addition of AHPS, the latices of stable and high-solid content (as high as 60%) were prepared. Flow of the latices follows the law of the Bingham body. The final diameter of the latex particles is 0.3-0.5 mum in diameter, which is larger than that of the conventional latex particles and decreases with the increase of AHPS and potassium persulfate (KPS) concentration. All the copolymers are atactic polymers, showed as single T-g on dynamic mechanical analysis spectrum. Compared with the copolymers that were prepared by surfactant emulsion polymerization, tensile strength, as well as water resistance is greatly improved.