2-Ethenyl-pyridine (EPD) was first used to successfully copolymerize with acrylonitrile (AN) in a H2O/dimethyl formamide (DMF) mixture by using azobisisobutyronitrile as the initiator. Kinetics of copolymerization and degradation of poly(AN-ran-EPD) were discussed. The kinetic equation of copolymerization and the apparent activation energy of degradation of poly(AN-ran-EPD) were obtained. In H2O-rich reaction medium, copolymerization followed the suspension polymerization more, but in DMF-rich reaction medium, copolymerization followed the solution polymerization more. Increase in DMF concentration in the solvent mixture lead to a rapid increase in the degradation apparent activation energy. The apparent activation energy decreased quickly with an increase in EPD concentration, and such a change became less prominent as the molar ratio of EPD/AN went beyond 3/100. (c) 2007 Wiley Periodicals, Inc.