In order for the joint research by Network of ASEAN-China Think-tanks (NACT) to reach out to a much wider audience, NACT began to publish joint research of all Working Groups since 2019. This book is a collection of research papers contributed by ASEAN and China scholars who attended NACT Working Group Meeting on Regional Cooperation for Sustainable Energy Development on April 16, 2019 and NACT Working Group Meeting on Environmental Protection in ASEAN and China on May 17, 2019. The contributing scholars give their ingenious and insightful thoughts on ASEAN-China energy and environmental protection cooperation from either a national or a regional perspective. Two NACT Working Group Reports are also incorporated in the appendices of this book, including innovative and practical policy recommendations on strengthening ASEAN-China sustainable energy and environmental protection cooperation in existing priority areas and identifying new ones.