This book provides an in-depth look at the current development of the fifth-generation mobile communication technology (5G) and artificial intelligence (AI), their technological advantages, application, and critical role in science and technology, as well as their future development trends. This book is divided into three parts. The first part details the current development of 5G around the globe and the evolution from 5G to 5.5G. The second part explores the significant developments in AI technologies, including typical AI technologies such as machine learning (ML), natural language processing (NLP), and computer vision (CV), and the popular foundation model technologies. The third part looks at the impacts of 5G+AI on the digitalization and intelligent development of industries and showcases some of the applications in government, meteorology, education, and healthcare, etc. This book can serve as a reference for a diverse range of readers, such as people in the public sector and the mobile communications industry, and faculty and students in this field.