This book focuses on the world openness, including the level of openness of 129 economies. This book discusses the latest World Openness Index that measures the level of 129 economies' openness. It also presents many currently hot-spot issues, such as the new changes in the world' s openness in the context of the COVID-19 pandemic, the status-quo and prospects of global manufacturing and financial openness, new areas of digitalization, green development and world openness. The core part of this book is the World Openness Index. The World Openness Index measures the level of openness of 129 economies. This index is significantly different from other similar indices, it covers a wider range, and the measurement method is deeply improved. This book also includes research by top Chinese scholars on recent hot issues of world openness, which will help readers to understand the current situation and trend of world openness, China's achievements in opening up and its attitude towards openness in the future.