The phase equilibria of the Ni-Ti-Zr ternary system at 1000 and 1200°C have been experimentally investigated by back-scattered electron, electron probe microanalyzer and x-ray diffraction. In the present study, the established isothermal sections were characterized by a series of binary phases, ternary compounds and solid solutions. The results show that nine threephase regions and one liquid region at 1000°C, whereas, four three-phase regions and one liquid region at 1200°C were experimentally confirmed.