This book describes the spallation material technology for the production of high-intensity neutron sources and the fundamental study of nuclear transmutation devices for long-lived fission products. The techniques relate to material performance evaluation in order to realize neutron production by spallation process due to high-energy protons; other quantum beams application to simulate the particular process and products under high energy proton bombardment to the materials, and the effect of nuclear heat generation brought by the proton beam energy deposit. After more than twenty years of activities, the latest research results are presented on the issues of the use of liquid heavy metals, mercury target, solid target, and radiation materials science that remain to be concerned.