The aim of this study is a new investigation into thermosetting resin cure by dielectric analysis. In a first part, a semi empirical model of cure conversion determination, firstly tested on epoxy systems, is applied to cyanate ester resins. Parameters of the previous equation are adjusted. Secondly, the same equation is improved in a case of non-isothermal conditions. In this aim, a thermal agitation contribution on dielectric signal is studied and modelled by means of a WLF approach. Then, in the last part, we show the possibility and the reliability of a direct WLF use to determine cure conversion. C-1 and C-2 parameters of WLF approach are calculated and compared to literature data. (C) 2001 Elsevier Science Ltd. All rights reserved.