This paper focused on designing of a new ubiquitous interface agent based on the ontology technology and interaction diagram with the backend information agent system, i.e., OntoIAS, in cloud computing environments. Through the techniques of packet decoding and recognizing, the agent employs the CURRL to transform user commands into internal canonical format to conveniently process those commands by OntoIAS, which can avoid numerous, jumbled, and incorrect information torrents that results in misunderstanding of the information intention of users. In this paper, we preliminarily proposed a ubiquitous interface agent with the Bluetooth, GPS, and Zigbee techniques and related interaction diagrams in cloud computing environments. The system prototype and experiment outcomes can also reveal the feasibility of the system architecture.