Liquid crystal (LC) displays dominating in the present market of flat panel displays are generally based on interactions of light and LCs. Recent progress in this field indicates that integrating photochromic molecules into LC materials enables one to photomanipulate unique features such as photoinduced phase transition, photocontrolled alignment, and phototriggered molecular cooperative motion, giving birth to their novel applications beyond displays. For instance, on connecting with three-dimensionally crosslinked elastomers, LCs show photomechanical and photomobile properties, converting light energy directly into mechanical work. Combining supramolecular cooperative motion with microphase separation of well-defined block copolymers, they exhibit controllable regular nanostructures on a macroscopic scale with excellent reproducibility and mass production. This book first introduces the basic knowledge on LCs in a step-by-step manner and then deeply discusses photoresponsive LCs in low-molecular-weight compounds or small molecules, polymers or macromolecules, elastomers, and block copolymers, respectively. The engrossing photoresponsive LC materials offer an effective and convenient chance to adjust properties of advanced materials by integrating photoresponsive molecules with LC properties, which has become one of the emerging topics in the present and future LC researches. This book comprehensively compiles the nature of this type of materials and the ongoing progress in this research area and uses graphs and figures extensively to enhance understanding especially of beginners. This book would be useful for students and primary researchers in soft materials and self-organized materials in both chemistry and physics. It may also serve as a reference for experienced researchers to keep up the current research trends in photoresponsive LC materials.