The book is a tour de force by a world renowned legal expert and senior diplomat. Its main feature is a well-balanced integration of diplomatic thinking and legal analysis, based on the 70-year diplomatic theory and practice in China. Rich in content and thought provoking, it systematically discusses the international law issues faced by China in the development of major country diplomacy with Chinese characteristics. The author creatively develops the concepts of Blue Diplomacy to refer to global ocean governance, Green Diplomacy to deal with climate change, Red Diplomacy to cope with anti-corruption, Digital Diplomacy for cyberspace governance, each with amplified amount of cases and materials. The author also deliberates the "one country, two systems" policy and the building of "community with shared future of mankind". The book helps the readers to better understand the fundamental principles and policies of China's diplomacy. For students, it is a key that opensup the door to international law studies; for researchers, it is a rich mine of international legal issues; for diplomats, it is a valuable guidance to master the art and science of legal diplomacy.