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Study on the mechanism of movement of animals has always been an important activity in academic researches. In recent decades the study of the motion of swimming and jumping in frogs and simulate the movements increased. on the work ahead by Modeled of how the study of the anatomy of frog leg muscle, a mechanism is designed to simulate the natural movement of the foot frog with just one operator. Provide a geometric approach to mechanism design, frog legs move according to the joint angles of the design. The major angular changes in the mechanism based on changing the angle of the frog's natural movement. Actuator has sinusoidal Circular motion and frog motion cycles can be created with different frequencies. Required frequency for Actuator obtains by given the speed linear motion of foot in a natural movement. Also by enter the drag force and the force generated by the foot frog swimming is simulated. Required torque for actuator is obtained by velocity and acceleration of motion. The results of simulations and compare them with results from the natural movement of the frog, represents the high resolution of mechanism to mimic the real motion of the leg and the frog swimming and matching the values of velocity and acceleration and the drag force and the axial force. According to the results, the designed mechanism can be used to simulation movement of different types of frogs in the swimming.