We consider that factors such as prosody of systems’ utterances and dialogue rhythm are important to attain a natural human-machine dialogue. However, the relations between dialogue rhythm and speaker’s various states in task-oriented dialogue have been not revealed. In this study, we collected taskoriented dialogues and analyzed the relations between “dialogue structures, kinds of dialogue acts (contents of utterances), Aizuchi (backchannel/acknowledgment), Repeat and interjection” and “dialogue rhythm (response timing, F0, and speech rate)”.