Abstract: By means of IR, NMR and elemental analysis etc., it is proved that the copolymerization of diethylene glycol bis(allyl carbonate) (DADC) and vinyl acetate (VAc) has been taken place. Effects of the compositions of copolymers on the mechanical properties of the resin castings were determined. The results show that DADC/VAc resin castings have a good processibility, their toughness and flexural strength are better than those of DADC homopolymer, and the apparent activation energy of the copolymerization obtained by Kissinger equation is 93.8 kJ/mol.