Abstract: The auto navigation system of intelligent car has the functions of automatic tracing,automatic recognition of track,and stable and rapid driving.The software of this system is designed based on CodeWarrior with using C language tool as development environment.The system core uses the single chip microcomputer MC9S12XS128B from Freescale company.And its peripheral circuit and chip driver’s circuits are designed by Protel 99SE.It uses CMOS digital camera to realize path recognition through the car's closed loop control.Simulation test shows that this system can content the path recognition and  has a good anti-disturbance capacity.At the same time its steering engine can adjust to fast response time,motor control is stable and the  dynamic performance is good.

Key words: intelligent car, CMOS digital camera, navigation system