Some kinds of functionally gradient materials have been produced in our laboratory by hot isostatic processing (HIP), using powders of copper and molybdenum themselves and their mixtures for the purpose of thermal stress relaxation. Then, both elements have remarkably difference in thermal conductivity. This paper refers to the mechanical and fatigue properties of products using powders of copper and molybdenum themselves and their mixtures. The functional gradient of one of the above products had been observed by an optical microscope and micro-Vickers hardness distribution. In addition, the static tensile and fatigue properties of the mixture exhibited a lower value as compared with those based on the rule of mixture. It can be seen under observation by a scanning electron microscope (SEM) that the specimens of copper and molybdenum show typical ductile fracture surfaces, while those of mixtures exhibit brittle ones.