This chapter mainly explores cutting-edge research and technologies in Human-AI Interaction (HAII) within the context of the metaverse and virtual reality (VR). It first distinguishes these two similar but different concepts, metaverse and VR, and then investigates the HAII technology and frontier research from the perspectives of human-intelligence-computer (i.e., user-AI-metaverse/VR interfaces) and human-intelligence-human (user-AI-user). Specifically, this chapter covers intelligent perception and optimization technology for detecting human emotions and interaction intentions in human–computer interfaces, the sense of the presence of users in the virtual environment, and AI-driven methods to enhance it, as well as the interaction methods, behaviors, and phenomena between humans in the virtual environments. Additionally, it explores intelligent technology that facilitates multi-user interactions. Finally, it proposes the challenges, key issues, and prospects of future research in the metaverse and VR from the perspectives of technology, interaction, society, and users.