To measure the current in the solenoid,a novel current s ensor based on the chirped effect of fiber Bragg grating (FBG) is proposed.The deformation of the rectangular cantilever beam is caused by the magnetic force from energized solenoid,on the disc-shaped soft iron and it resu lts in the bandwidth change of the reflection spectrum of FBG that is mounted at side of the cantilev er.The change of bandwidth of the reflection spectrum of FBG is directly proportional to the square of the current intensity.The change of bandwidth is insensitive to temperature in the system.W hen the optical spectrum analyzer is with a resolution of 0.02nm, the measuring range of the sensor is up to 27.1－1000mA.Expe rimental results show that the 3dB bandwidth change is less than 5pm when the temperature changes from －15℃ to 45℃.The experimental results a re consistent with theoretical results,and the sensor scheme is feasible.