The performance of various types of control systems for an electric governor of a diesel engine was examined. The amount of fuel injection of diesel engine is usually controlled by an electric governor system in these decades, and a PID controller is installed for the electric governor. Even when the optimal parameters for PID controller are well tuned, it is difficult to keep constant rotating speed of the engine, because the applied load to generators may vary according to its running conditions. In this research, a neural network was applied to regulate the parameters in PID controller to control the amount of fuel injection. Experimental studies show that the parameter regulation system using neural network presented here had good performance under various running conditions.