The thermal stability and nonisothermal thermal decomposition kinetics of the vinyl chloride-vinyl acetate copolymer synthesized via microsuspension polymerization (MS-VC/VAc) were studied by dynamic TG. The results showed that MS-VC/VAc gives off hydrogen chloride and acetic acid (HAc) at the same time when it was heated. VAc content produces little effect on the thermal stability and the kinetic parameters. The activation energy for giving off HCl and HAc is in the range of 120-160 kJ/mol and the Arrhenius frequency factor 3.27 x 10(9)-9.72 x 10(12) s(-1). For different heating rates, the kinetic model function of the thermal decomposition obeys the Avrami-Erofeev model equation, that is, [-ln(1-a)](1/m) for g(a), where m = 0.65-0.85.