A passive dynamic walking robot can walk down a gentle slope naturally without any actuator or controller, only by potential energy. Therefore, it is thought that the principle of walking exists in this phenomenon. By current researches, the passive dynamic walking has been confirmed for 2,4,and more than 6 legs. In the previous research, it was verified that a body of multi legged Passive Dynamic walker affected its gaits. In this research, the effect of body element of a quadrupedal Passive Dynamic Walking robot was analyzed in more detail on a simulator.