A novel gel actuator exhibits a peristaltic motion is designed. We proposed a new approach of coupling an acid autocatalytic reaction and a pH-responsive gel in order to cause contraction waves. The poly(AAm-co-AAc) microphase-separated tubular gel was synthesized, which can be inflowed reaction solution to its hollow. We focused on its kinetics and evaluated the characteristics of the microphase-separated gels. And we also demonstrated that the propagation of the contraction region occurs in the tubular gel. Our final goal is to develop a biomimetic chemical robot which realizes a peristaltic locomotion by forming contraction waves like a snail.