Abstract: Gyro North Finder is widely used in the military and civilian fields. A North Finder system incorporated with a Fiber Optic Gyro (FOG) is introduced in this paper. The system combined computer with DSP, which is used to capture gyro output data and control system. It communicates with computer by RS232 serial port. Data filtering, data resolving and real-time display are executed by computer to find the north. The initial azimuth angle is given by computer when the North is found, and the North is indicated by a beam of laser. The accuracy of the final FOG North Finder system reaches 3to 10 mil. The system can meet the requirements for military and civilian applications.