This book is written by subject experts based on the latest research results on the characteristic line method of stress wave propagation in rock masses. It establishes a framework for stress wave propagation analysis methods under three levels of rocks, joints and rock masses. It introduces the two-characteristic line method for stress wave propagation in rocks, and further illustrates the modified characteristic line method for stress wave propagation in complex jointed rock masses. The split three-characteristic line method was proposed for stress wave propagation in rock masses with macro-joints and micro-defects. The book focuses on the basic theory, and highlights the ideas, methods and steps to solve the problem of stress wave propagation in rock masses. This book can be used as a reference book for researchers of research institutes engaged in analyzing, predicting and controlling dynamic stability in rock, geological, and mining engineering. ​