To model a physical system needs many various aspect of system behaviour. Usually, the result is in the differential equation. There are many methods in finding this model, one of them is Bondgraph. This paper will discuss how to use this method to model simple physical system and simulate it using 20-Sim software from University of Twente, The Netherlands. The experimental result shows that we can build a model using Bondgraph easily. In 20-Sim, there are several facilities that will enable user to simulate both in graphics or 3D model