Lignin is one of the most abundant plant-derived feedstock on earth and qualifies as a renewable material. However, lignin is widely recognized as waste byproduct of the cellulosic ethanol and pulp and paper industry. How to properly modify lignin and develop it into functional polymers is a huge challenge, but an attractive research topic in both industry and academia.This book brings together leading engineering approaches to address the challenges of lignin valorization. It presents the chemistry and properties of different types of lignin, and explores the cutting-edge approaches of lignin modifications. Unlike any existing texts, this book not only summarizes the traditional ways of using lignin, but also presents various potential applications of lignin materials together with advanced processing techniques.The basis of lignin (its chemistry, types and properties) is described, as are different approaches to modify it. The features of lignin and its copolymers are explored and aligned with their potential applications. In addition to the carbon materials from lignin, the advanced fabrication approaches to engineer lignin-based micro/nano-structural materials are summarized.