A Three body problem (3BP) considers three mutually interacting particles. It is a problem that is surprisingly difficult to solve. This simple Maplet application simulates the 3BP numerically. Users can set paramters and see how the particles behave. Some examples are included in the application such as a line solution, triangle solution and figure 8 solution. 1. Select a particular example from the pull down menu and the simulation starts automatically. 2. You can also set parameters, mass, position, velocity of three particles. After setting the parameters, press the Start button to start the simulation.