In this paper we dscribe that emotional synchronization is effective to a KANSEI communication system. We developed a robotic KANSEI communication system using entrainment of dynamics, and its effectiveness was examined by experiments of human-robot communication. The robotic emotion was entrained to human emotion by using a vector field of dynamics. The robotic facial expression using a communication robot "Kamin_FAl" was realized dynamically based on the robotic emotion. In the experiment of communication, the human impression was changed by the strength of synchronization of robot. Then we confirmed that this method could utilize human-robot communication to keep a comfortable state.