This book constitutes the proceedings of the 20th EAI International Conference on Communications and Networking in China, ChinaCom 2025, held in Xi'an, China, during November 8–9, 2025.

The 42 full papers included in this book were carefully reviewed and selected from 106 submissions. They are organized into the following topical sections: Wireless Signal Processing, Modulation, and Receiver Design; Security, Privacy, and Trust; Air-Ground Networking and Low-Altitude Intelligent Systems; Edge Computing; Sensing and Localization; and Internet of Things.