Advances in laser technology over the last 10-15 years have stimulated study of the active control of quantum molecular dynamics. Lasers may used to generate external fields of varying intensity, phases, and spectral content, which then are used to alter the molecular dynamics of a system so as to generate more of a particular product. Control of reactions at this microscopic level is one of the hot areas of research in chemical physics. This book describes the current status of the theory of optical control of molecular dynamics