Abstract: The fibre optic amplitude monitor is developed by our institute as a non contact vibration measuring system for rotator blades,in which a magnetic needle is adopted as a one per rotation sensor and a fibre optical cable as a blade passing sensor.Multiple application of the present monitor in development of new type engines demonstrates reliability and convenience in operation.It features high temperature resistance,it can work up to 350℃ and up to 400℃ in the near future.This monitor has been put in service as a main instrumentation to monitor the blade vibration in the high pressure compressor of our new type engine during its development.