Abstract: Spallation behavior of a kind of tungsten alloy, with composition percent by weight W90%-Ni6.8%-Fe2.7%-Cr0.5% and manufactured by powder metallurgical method, was investigated by using a compressed gas gun as impact loading device. The peak stress in target is 5~10 GPa, stress duration 0.2~0.6 s. The stress history measured by manganin gauge embedded in target/window interface demonstrated that the spallation strength of the tungsten alloy is a monotonic increasing function of square root of tensile stress rate and independent on the peak stress level. Metallographic analysis for the recovery sample showed that the tensile fracture of the tungsten alloy occurs mainly in the Fe-Ni mixture region with a few transcrystalline fracture in tungsten grain and there exhibits many cup-like pits on the fractographic surface as well. It can be seen from those mentioned above that the tensile fracture of the tungsten alloy is essentially contributed to the ductile fracture mechanism.