This computer controlled inverted pendulum system can be used for investigated of different nonlinear control techniques. Based on the linear system model, digital controllers such as PID type, optimal state, and fuzzy logic, etc. can be implemented on this system. Moreover, the software accompained minimizes the need for external test equipment. Typical system consists of a personal computer, an I/O card, an inverted pendulum assembly, a PWM power amplifier, a power supply unit and number of test and control programs.