<正> Effects of N-alkyi substituted ethylenediamine derivatives on vinyl polymerization using persulfate as initiator were studied. The apparent kinetic equations and overall activation energies of acrylamide polymerization were determined using the above mentioned system as initiator. The promoting activities of different diamine derivatives on vinyl polymerization are in the order of tertiary diamine>secondary diamine>primary diamine. Diamines having methyl groups as the substituent on their nitrogen atom possess higher promoting activity than that of having larger alkyl groups. The initial free radicals produced through the redox reaction of persuifate and diamines were studied by spin strapping technique and ESR spectroscopy. The results obtained confirm the fact that the initial free radicals of the diamine species can initiate vinyl polymerization and become the amino end group of the resulting polymers.