The kinetics of the transesterification of dimethyl terephthalate(DMT) with ethylene glycol(EG) was kinetically investigated in the presence of various ceramics. The thermal and mechanical properties of PET filled with various ceramics were characterized by DSC, TGA and tensile testing. The conversion was calculated from the quantity of distilled methanol. The rate constants(K3) was calculated according to the theoretical equation of Tomita. Based on these results, value of ZnO was the highest and that of Al203 was the lowest. The activation energy of ZnO was calculated from a plot of Iogka vs. In as E. : 39.42k11mo1. This value was lower than that of Zn-acetate(42.19k11mo1). From these results, we demonstrated that the reactivity of ZnO is very high. The thermal property of PET Slled with various ceramics was not changed, but the mechanical property was decreased due to the lack of interfacial bonding between ceramics and PET.