This paper describes Ambient Party Room, which is a room-shaped information environment for party situations. This system estimates the conversation states by measuring participants' nonverbal cues and displays various types of information to stimulate the conversation. In this study, we reconstructed the system architecture from an early prototype and newly examined several types of information stimulus using a floor display, wall displays, and speakers. We conducted an experiment in which six participants talked freely in Ambient Party Room. Results showed that both profile-based information stimulus and feedback information of participants' behaviors contributed to their activated conversations.