The kinetics of emulsion polymerization for the more hydrophilic monomer VAc is studied. The effect of free radical desorption and the contribution of the polymerization in aqueous phase to total polymerization rate are analyzed. A mathematical model for stage II and I of emulsion polymerization of VAc is proposed. It can be successfully used to predict the polymerization rate
the distribution of free radicals among latex particles and the change of the average number of free radicals in one particle along with monomer conversion. The model prediction and experimental data are compared and discussed.