Polymerization systems of vinyl acetate that retain the homogeneity regardless of the ratio organic/aqueous phases were studied. The organic phase consisted of 30/70 monomer/alcohol solutions and the aqueous one of solutions of nonyl phenol etoxylated with 25 moles ethylene oxide in 33% water. Ethanol was used in homopolymerization and n-propanol in copolymerization. Copolymerization was performed with di-2-ethyl-hexyl maleate. In the homogeneous systems obtained, the surfactant complexes the initiator, ammonium persulfate, while the cosurfactant modifies the initial structure of water. Owing to these phenomena, the structure of the reaction medium changes according to the ratio of phases. The rate of initiator decomposition and of polymerization depends on the ratio of phases. In presence of soluble initiator in the organic phase, AIBN, the rate of copolymerization is proportional to the content of the comonomers if the final system rest homogeneous.