Bulk metallic glass Zr52.5Ni14.6Al10Cu17.9Ti5 was prepared by melt injection casting method. Its glass transition and crystallization temperatures were determined by differential scanning calorimetry （DSC） to be 631 K and 710 K respectively. By analysis of X-ray diffractometry （XRD） and transmission electron microscopy （TEM ）, the predominant crystallized phase of Zr2Ni0.67O0.33 distributed on glass state matrix was detected after annealing at 673 K for 600 s. The transformation to Zr2Ni0.67O0.33 and a small amount of ZrAl and Zr2Cu took place after annealing for 600 s at temperature from 703 K to 723 K. With increasing annealing temperature from 753 K to 823 K, the amounts of ZrAl and Zr2Cu increased, but the size of the crystals did not significantly change. The transformation to Zr2Ni0.67O0.33 is interface-controlled, but is diffusion-controlled to Zr2Cu and ZrAl. With increasing annealing temperature up to 200 K above Tx, the nanometer grains became very fine because of the increase of nucleation rate for Zr2Cu and ZrAl.
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