According to the characteristics of operating procedures of gasoline engine idle speed; a fuzzy control method is developed to control idle speed of gasoline engine. A novel controller is designed. The controller, which combines fuzzy logic algorithm with traditional PID algorithm, improves steady and dynamic performances of idle speed control. The method has the advantage of not requiring a precise mathematical model of the controlled object. By using SIMULINK simulation software of MATLAB, the simulation results obtained with the PID fuzzy controller show that the PID fuzzy controller has better controlled performances and robustness. It provides some reference values for further practical application.