Book excerpt: This book constitutes the refereed proceedings of the 7th International Conference on Smart City and Informatization, iSCI 2019, held in Guangzhou, China, in November 2019. The volume presents 52 full papers, which were carefully reviewed and selected from 139 submissions. The papers are organized in topical sections on Internet of Things (IoT) and smart sensing; urban computing and big data; smart society informatization technologies; cloud/edge/fog computing for smart city; applications for smart city informatization; assistive engineering and information technology; cyberspace security; blockchain and applications.