Differential scanning calorimetry results under non-isothermal conditions of the chalcogenide Se80-xTe20Sbx (x=1.5,7.5, and 9 at%) glasses are reported and discussed. The models, used for calculating the crystallization kinetics from the exothermic peaks, have been applied to obtain the pre-crystalliation kinetics from the endothermic peaks. Increasing Sb content was found to increase the astivation energy of glass transition.