The crystallization behavior of Cu45Zr48Al7 bulk metallic glass was studied by differential scanning calorimetry (DSC) and x-ray diffraction (XRD). Cu45Zr48Al7 bulk metallic glass exhibits two-stage crystallization in heating process. The crystallization peak temperature Tp1 and Tp2 shifted to higher temperature with increasing heating rate. It was found that the crystalline phases homogeneously nucleared at a constant rate and grew linearly at a constant rate in the supercooled liquid. Different bulk nanostructured alloys can be derived from Cu45Zr48Al7 bulk metallic glass by changing the heating rate and/or annealing temperature.