This book systematically summarizes China Internet development over the past 25 years, highlighting its strong impact on China’s economy and society, and discussing the Chinese people’s transition from beneficiaries and participants to builders, contributors and joint maintainers of cyberspace development. It describes the development achievements, status and development and trends in China Internet in 2019, systematically summarizes the main lessons learned during development, and analyzes China’s strategic planning and policy actions. Further, it discusses topics such as development outcomes, future trends in information infrastructure, network information technology, digital economy, e-government, construction and management of network contents, cyberspace security, the legal construction of cyberspace, and international cyberspace governance. In addition, the book suggests improvements to the index system for China Internet development and offers an overall assessment of cyberspace security and informatization work throughout China in order to comprehensively and accurately demonstrate the level of China Internet development.