Zr45.1Cu42.3Al8.7Si1.4Y2.5 (at. %) metallic glass alloy was prepared by using copper mould casting. The crystallization behaviors of the alloy during continuous heating are investigated mainly by differential canning calorimeter (DSC). The activation energies were obtained from the Kissinger and Doyle equations. The results show that the activation energies of glass transition (Eg), crystallization (Ex) and peak crystallization (Ep) are 365kJ/mol, 281 kJ/mol and 279 kJ/mol, respectively. The crystallization activation energies are all less than the corresponding data of ZrCuAlSi alloy, the results show that thermal stability was decreased with the Y addition.