The oxygen absorption and oxidation of acrylic esters will promptly increase in the presence of phenyl hydrazine and polymerization will proceed by using 0.1—1％ of phenyl hydrazine．Both the rates of oxygen absorption and the rates of polymerization of several me-thacrylate esters were studied and shown to be with the following order：M→ethoxyethylmethacrylate(M→EMA) Hydroxypropylmethacrylate (HPMA)>M→ehtyl metliacrylate(MMA) The oxidation mechanism of acrylic esters in the presence of phenyl hydrazine has been proposed that the latter may withdraw the proton situated at a-carbon atom of the ether linkage or of the double bond in order to facilitate the oxidation to form the hydroperoxide．