Different poly(methyl methacrylate/n-butyl acrylate)/poly(n-butyl acrylate/methyl methacrylate) [P(BA/MMA)/P(MMA/BA)] and poly(n-butyl acrylate/methyl methacrylate)/polystyrene [P(BA/MMA)/PSt] core-shell structured latexes were prepared by emulsifier-free emulsion polymerization in the presence of hydrophilic monomer 3-allyloxy-2-hydroxyl-propanesulfonic salt (AHPS). The particle morphologies of the final latexes and dynamic mechanical properties of the copolymers from final latexes were investigated in detail. With the addition of AHPS, a latex of stable and high-solid content (60 wt %) was prepared. The diameters of the latex particles are similar to0.26 mum for the P(BA/MMA)/P(MMA/BA) system and 0.22-0.24 mum for the P(BA/MMA)/PSt system. All copolymers from the final latexes are two-phase structure polymers, shown as two glass transition temperatures (T(g)s) on dynamic mechanical analysis spectra.