Mechanical, chemical and thermal properties of thermoset materials such as epoxy resins are conditioned by cure schedule. There are different techniques to determine the resin conversion level during process such as Fourier-transform infrared spectroscopy (FTIR); in this study we analyze the curing of two comercial systems of DGEBA/DDM by this technique. The conversion level of epoxy groups was evaluated employing typical stretching of epoxy groups as 917 and 863 cm -1 , and by the use of two different reference stretching 1610 and 1510 cm -1 . Different conditions of curing and poscuring have been analized.