The crystallization behaviour of Ni67Zr33 amorphous alloy has been studied by using transmission electron microscopy. Two metastable phases, T0 and T1, have been found at 500℃. The T1 phase has a body centred orthorhombic er pseudo-tetragonal lattice (α≌b=0.89 nm, c=3.14nm) and the Ibα2 or Ibαm space group. As the temperature increases, the metastable phases gradually change into the stable phase T2(Ni10Zr7) containing a lot of faults. The diffraction streaks parallel to c* with h+k ≠ 2n can be explained satisfactorily by the 1/2(α+ b) displac ement of (001) plane in T2. The final stable phases are Ni10Zr7 and Ni21Zr8.