This unique book is devoted to physics of relativistic laser plasma and its applications in the production of particle beams and radiation sources. This field has emerged as a new frontier of interdisciplinary research covering nonlinear optics, plasma physics, accelerator physics, and nuclear physics owing to the development of a few key technologies such as ultrafast high power laser, micro-fabrication, and ultrafast detection. Written by active leading experts, the book is composed of ten independent chapters, which cover laser-plasma-based particle beams and radiation sources, the involved physics, recent progress, as well as their potential applications. It provides a comprehensive overview of major topics in this field, which is particularly useful to young researchers. It also provides senior researchers specialized in certain subjects with an overall vision of this field.