The purpose of our research is to develop lifelike behavior in a communication robot, which is expected to potentially make human-robot interaction more natural. Our previous research demonstrated the importance of a robot’s contingency for lifelikeness [1]. On the other hand, perfect contingency seems to give us a non-lifelike impression. In order to explore the appropriate contingency for communication robots, we developed a robot system that allows us to adjust its contingency to an interacting person in a simple imitative interaction. As a result of an experiment, we identified the relationships between the degree of contingency and the subjective impressions of lifelikeness, autonomy, and preference. However, the experimental result also seems to suggest the importance of the complexity of interaction for investigating the appropriate contingency of communication robots. Categories and Subject Descriptors H.5.2 [Information Interfaces and Presentation]: User Interfaces -Interac...