Abstract: An experimental study on robotic fish's turning maneuverability with the sequential image processing is conducted. First,the robotic fish's motion process is recorded with a high-speed camera.Then,by processing the sequential swimming images,the backbone curves of robotic fish is extracted,and the dynamic characteristics of turning angle,angular velocity,and the angular acceleration are obtained.According to the experimental result,the movement features of three phase stages of C-shape-turn are presented,and the differences between theoretical and practical motion parameters are analyzed. The static and dynamic C-shape-turn movements are compared,and the influencing factors are analyzed,including the initial kinetic energy and the angle in the holding phase.On this basis,several effective ways to improve the robotic fish's turning maneuverability are proposed.