Abstract: The design problem of water strider robot is discussed.A set of algorithms for designing the size of the actuating leg are proposed.The methods and an instance to design the structure,control system and software of the robot are presented.A prototype driven by two electric motors is developed and tested in experiments.The prototype tele-controlled with infrared signals has the capability of turning and speed governing.As a bionic robot of the water strider,it is featured by light weight,tiny volume and low power consumption.The experiments show that it performs better than other current prototypes of the water strider robot.