The curing reaction between the diepoxy and dicyanate mixed resins in the presence of three different catalysts Cu(AcAc)(2), manganese octoate, and copper octoate was investigated. The thermal behavior was monitored using differential scanning calorimeter; the transformations of structures during the isothermal and heating process were explored by Fourier transform infrared spectroscopy; the changes of the carbonic-framework of polymer and intermediate products were analyzed by nuclear magnetic resonance. Conclusions can be drawn as follows: Similar to noncatalyzed system, the overall reaction Still Occurs in two steps: cyclotrimerization of cyanate ester to produce triazine rings, coupled with the formation of some secondary intermediate products, and coreaction of epoxy and triazine rings to form oxazolidinone rings at high temperature. The catalysts can accelerate the Curing process and decrease the curing temperature as well as get time, and manganese octoate presents the best effect on curing rate. But the mechanisms and the structures of intermediate products of metallic-catalyzed epoxy/cyanate are not changed by the addition of catalysts. (c) 2006 Wiley Periodicals, Inc.