The glass formation and devitrification of alloys in the Cu-Ge-Te system were studied by differential scanning calorimetry. A comparison of various simple quantitative methods to assess the level of stability of the glassy materials in the abovementioned system is presented. All of these methods are based on characteristic temperatures such as the glass transition temperature, T-g, the onset temperature of crystallization, T-in, the temperature corresponding to the maximum crystallization rate, T-p or the melting temperature, T-m. In this work, the parameter K-r(T) is added to the stability criteria. The thermal stability of some ternary compounds of the CuxGe0.2-yTe0.80-x+y type has been evaluated experimentally and correlated with the activation energies of crystallization by this kinetic criterion and compared with those evaluated by other criteria.