Polyhedral oligomeric silsesquioxane (POSS) can be incorporated into polymers to obtain organic/inorganic hybrid materials. Octaepoxysilsesquioxane (E-POSS) with eight reactive epoxy groups per molecule is an important kind of POSS. E-POSS was cured with 4,4'-diaminodiphenylsulfone diamine (DDS) in this study. The curing kinetics of the E-POSS/DDS system was studied by using differential scanning calorimetry (DSC). Kinssinger and Flynn-Wall-Ozawa methods were used to obtain the activation energy and pre-exponential factor of the curing reaction.