Communication infrastructures play a key role in a smart grid. In particular, the multiagent system (MAS) will have a wide application in microgrids, which are the basic subsystems of modern power systems. In this article, the cyberphysical paradigm for a communication MAS in a smart grid application is introduced. The state of the-art in this field is reviewed. First, the structures and concepts of MAS for smart microgrids are presented. Then, the technologies of communication and computation infrastructure in the physical layer, as the hardware of communication systems, are reviewed. Finally, the methodologies for data transmission, processing, decision, and optimization in the cyber layer are discussed. A feasibility study of Internet of things devices and technologies including cloud and edge computation for MAS in microgrids has been conducted.