The kinetics of emulsion polymerization of vinyl propionate (VP) using the redox system potassium persulfate (KPS)/acetone-sodium bisulfite (ASBS) as redox pair initiation system is studied at 25-degrees-C. The effect of different initiator concentrations on the rate of polymerization and on the number and size of particles of the formed emulsion latices is established. The polymerization proceeded smoothly till high conversion and yielded stable emulsion latices. The rate of polymerization was found to be dependent on the initiator concentration to the 2/5 power.