Building on existing research, this book establishes a research framework for state learning under open conditions by integrating relevant theories such as the internalization of international mechanisms and national socialization. The book introduces a model of state learning with two dimensions: the level of state learning (instrumental, normative) and the proactiveness of state learning (follower, leader), effectively explaining the changing process of China's climate policy at different stages. Furthermore, the book compiles rich data around global climate governance mechanisms and the evolution of China's climate policies, providing insights into the development and changes in the global climate governance system and China's domestic climate policy. In terms of theory and content, the book offers value and innovation. Its key features include: 1. Introducing a research framework for state learning under open conditions, interpreting changes in state policy and behavior from the perspective of state learning. 2. Systematically organizing the development process of the global climate governance system and China's national climate policies, analyzing in detail the interaction between the two. 3. Combining theoretical depth with a certain level of accessibility and knowledge dissemination.