The kinetics of the glass transition of Zr57.2Al21.4Ni21.4 bulk metallic glass (BMG) was studied using differential scanning calorimetry (DSC) with continuous heating of the sample at various heating rates. The heating rate dependence of the glass transition temperature (T-g) was investigated. By employing Moynihan and Kissinger models, the activation energy (E) of the glass transition was determined. It was shown that the transition process cannot be described in terms of single activation energy. The variation of E with the extent of conversion (alpha) was further analyzed by using two isoconversional methods (Kissinger-Akahira-Sunose method and Vyazovkin method). Evidence of the variation of E throughout the glass transition region was observed, which indicated that the transformation from amorphous to a supercooled liquid phase of Zr57.2Al21.4Ni21.4 BMG was a complex process. (C) 2011 Elsevier B.V. All rights reserved.