X-ray diffraction (XRD) and differential scanning calorimetry (DSC) were employed to investigate the influence of Ni content on the crystallization of amorphous Zr70Cu30 xNix (atom fraction in %) alloys. Experimental results show that with the Ni content increasing the activation energies for crystallization of amorphous Zr70Cu30-xNix alloys increase correspondingly, indicating that the thermal stability is greatly improved. All the DSC traces of amorphous Zr70Cu30-xNix alloys exhibit two exothermic peaks, suggesting that the crystallization process proceeds via a double-stage mode. The first exothermic peak at lower temperature mainly corresponds to the precipitation and growth of Zr2Cu particles, while the second one corresponds to the precipitation of nano-scale Zr2Ni phase and crystallization of residual amorphous phase. The mechanism on the crystallization of amorphous Zr70Cu30-xNix alloys was discussed.