Differential scanning calorimetry data at different heating rates on Se0.7Te0.3 chalcogenide glass are reported and discussed. From the heating rate dependence of values of Tg, Tc and Tp, the glass transition activation energy, Et, and the crystallization activation energy, Ec, were derived. The crystallization data are interpreted in terms of recent analyses developed for non-isothermic crystallization and also for the evaluation of Ec and the characterization of a crystallization mechanism. The results indicate that bulk crystallization with two-dimensional growth occurs for this glass. The calculated Et and Ec are 143± 3 and 174± 8 kJ/mol, respectively.