The crystallization kinetics of bulk Ge10Sb30Se60 glass has been studied by differential scanning calorimetry. The effective activation energy of crystallization has been evaluated on the basis of the Kissinger equation and the isoconversion cuts method. The empirical Sestak-Berggren model has been used for the description of DSC crystallization data as it provides the best fit to the experimental results. It has been found that the Johnson-Mehl-Avrami model could not be applied because of the influence of the nucleation process during crystallization.