Results of differential scanning calorimetric (DSC) under isothermal and non-isothermal conditions on Se0.7Te0.3 glass are reported and discussed. By using the Johnson-Mehl-Avrami equation, the effective activation energies for crystal growth, EG, have been evaluated and the crystallization mechanism has been studied. The results indicate that the crystallization process is a two-dimensional growth. The average value of EG is 150± 7 kJ/mol.