Abstract: A cruise control system based on Matlab and fuzzy PID (proportional-integral-derivative) control for automobile was proposed and was composed of analog signal input device, electronic control unit of cruise control system, throttle actuators and so on. In order to improve accuracy and stability of automobile cruise, a self-adapted PID fuzzy control algorithm was proposed and the fuzzy rules and proportion factor of fuzzy output were optimized in this algorithm, in which the advantages of conventional fuzzy control not only was retained，but also performance of cruise control system was improved this algorithm. Vehicle (Shanghai Volkswagen Passat 1.8 MT) test results showed that when vehicle (Shanghai Volkswagen Passat 1.8 MT) cruised at constant speed 40, 60, 80, 100 km/h, stable time of the automobile cruise control system was at 38, 53, 65, 80 s, and overtake speed was at 0.5, 0.4, 1.2, 1.0 km/h, respectively. The system proposed in this paper eliminates the automobile error effectively with rapid response, keeps in small overstake speed and works stably, which meets the need of control for automobile cruise control system.