Homopolymers of methyl vinyl ketone and its copolymers with styrene were prepared by the emulsion polymerization using divinylbenzene as a crosslinking agent. The quantitative effect of styrene and divinylbenzene on the colloidal Stability, degree of crosslinking, and swelling ratio was investigated by measuring density and viscosity. The viscosities of latex particles decrease drastically with increase of crosslinking agent and content of styrene. The reactivity of particles was analyzed by the product with hexamethylenediamine, of which -C=N- bonds were mostly observed in the condensation reaction between carbonyl and amino groups. The stability of the emulsion particles was maintained even after the reaction and the extent of reactions decreased with the crosslinker.