Abstract: Mechanical properties and fraction aspects of tungsten alloy 90WNiFe were investigated at temperatures from 25 ℃ to 900 ℃,and the effects on the microstructure and mechanical properties along with temperature changes were obtained.The results showed that along with the increase of temperature,tensile strength decreases;the fracture aspects change from tungsten cleavage and binder fracture to tungsten-binder interface decohension.The change of fracture modes is the main factor influencing tensile strength.The elongation firstly increases and then decreases with the increase of temperature,attaining a maximum value at about 350 ℃.The change of elongation results from not only the fracture mode but also the harmonious deformation between matrix and tungsten particles.