Results of differential scanning calorimetry (DSC) at different heating rates on Se0.8Te0.2chalcogenide glass are reported and discussed. From the variation of heating rate (a ) the crystallization fraction (x), heat flow difference (D q) and the crystallization peak temperature (Tp), the value of the effective activation energy for growth (Eg) was evaluated by six different methods. The Se0.8Te0.2 chalcogenide glass has two crystallization mechanisms, one-dimensional and surface crystallization growth. The average value of Eg for Se0.8Te0.2 chalcogenide glass is equal to (123.5 ± 5.7) kJ/mol. All the methods used to evaluate the effective activation energy for growth (Eg) are valid to discuss the results of glass-crystalline transformation but with differing accuracies.