This book constitutes the refereed proceedings of the 5th EAI International Conference on Smart Grid and Internet of Things, SGIoT 2021, held in TaiChung, Taiwan, in December 2021.The 9 regular papers and 4 short papers presented were carefully reviewed and selected from 57 submissions.

Applications on Internet of Things.- Intellectual Property Protection of Zhuang Nationality Funeral Culture on Internet of Things.- China IoT UBI Car Insurance Regulatory Development Trend.- Constructing a violence recognition technique for elderly patients with lower limb disability.- Aquaculture Monitoring Systems based on Lightweight Kubernetes and Rancher.- Design and Implementation of Water Monitoring Using LoRa and NB-IoT.-  InterWorking Function for Mission Critical Push To Talk Services.- Communication Security, Big Data, Neural Networks and Machine Learning.- Lightweight Privacy-Preserving Data Aggregation Scheme Based on Elliptic Curve Cryptography for Smart Grid Communications.- Design and Implementation of Distributed Image Recognition App with Federal Learning Techniques.- Improving Vision Clarity and Object Detection Accuracy in Heavy Rain Base on Neural Network.- An Enhanced Location-data Differential Privacy Protection Method Based on Filter.- Big data grave register information management system outside cemeteries under Internet of Things.- Machine Learning-based Models for Monofacial and Bifacial PV Module and Critical Model Feature Selection.- Study on the discovery of personal information on the network of people diagnosed with COVID-19.