There are some systems that are yet to be modelled using certain methods. One of them is Rotary Inverted Pendulum (RIP) on a wheeled cart which is yet to be modeled using the bond graph technique. Therefore, this work explored the bond graph technique for this system. Using this technique, which uses the concept of energy (power) transfer between elements in a system, the system was modeled. Then, the state space equations of the system, which give the first-order differential equations, were derived. It was observed that the system has five state variables because of the five integrally causal storage elements.