Abstract: The curing kinetics of flexible unsaturated polyester/methyl methacrylate resin (FUP/MMA) and flexible unsaturated polyester resin/coal fly ash (FUP/MMA/CFA) system was studied with nonisothermal DSC.The apparent activation energy (E_a), pre-exponential factor (A) and reaction order (n) were obtained, where E_a= 81.578 kJ·mol^-1, lnA = 20.40 s^-1and n= 0.937 7 for FUP/MMA system and Ea= 77.231 kJ·mol^-1, lnA= 19.15 s^-1and n = 0.935 9 for FUP/MMA/CFA system with Kissinger method, Ozawa method, ASTM E698-79 method and Crane equation. Based on these parameters, kinetic equations for the curing of FUP/MMA and FUP/MMA/CFA systems were established. Gelling temperature, curing temperature and treating temperature for each system were determined by extrapolating Tβ.