The latent properties and cure behaviors of an epoxy blend system based on cycloaliphatic epoxy (CAE) and diglycidyl ether of bisphenol A (DGEBA) epoxy containing N-benzylpyrazinium hexafluoroantimonate (BPH) as a thermal latent initiator were investigated with near-infrared (N-IR) spectroscopy. The assignments of the latent properties and cure kinetics were performed by the measurements of the N-IR reflectance for epoxide and hydroxyl functional groups at different temperatures and compositions. As a result, this system showed more than one type of reaction, and BPH was an excellent thermal latent catalyst without any coinitiator. The cure behaviors were identified by the changes in the absorption intensity of the hydroxyl groups at 7100 cm(-1) with different composition ratios. Moreover, characteristic N-IR band assignments were used to evaluate the reactive kinetics and were shown to be an appropriate method for studying the cure behaviors of the CAE/DGEBA blend system containing a thermal latent catalyst. (C) 2000 John Wiley & Sons, Inc.