The glass transition and non-isothermal crystallization behavior of Ge20Se70Sn10 glass prepared by the melt-quenching technique was investigated using differential scanning calorimetry (DSC) at continuous different heating rates. The structure and surface morphology of asprepared and annealed samples were characterized using X-ray diffraction (XRD) and scanning electron microscopy. The as-prepared samples showed the amorphous glassy nature, while the annealed ones are polycrystalline. Furthermore, XRD phase analysis allowed us to find the SnSe2, GeSe2, Ge4Se9 and Sn0.5 SeGe0.5 phases in the annealed samples. According to the value of Avrami index (n), the crystallization process of studied composition has more than one crystal growth mechanism. In addition, the results of DSC showed that the investigated glass has only a single glass transition and double crystallization stages. Furthermore, the activation energy of transition as well as the crystallization has been determined based on different approximation methods. In addition, the experimental DSC data of the first and second crystallization peak were compared with that calculated with the Johnson–Mehl– Avrami and Sestak–Berggren SB(M, N) model. The results revealed that the SB(M, N) model is more suitable for describing the crystallization kinetics of studied glass.