Abstract: Active magnetic bearing (AMB) is widely applied in many industrial fields.When the rotor becomes larger and larger,it is more difficult to manufacture a laminated rotor.Hence,solid rotor is utilized in the large rotor AMB system.Eddy currents are caused inside the rotor when a solid rotor rotates in a radial magnetic bearing.The eddy currents change the magnetic field of the radial magnetic bearing and,therefore,the forces on the rotor include not only the levitation force but also the tangential force.The tangential force causes magnetic damping and losses.This paper presents a magnetic field analytical model of magnetic bearing solid rotor system, and the forces and losses within a practical AMB system are calculated.It is shown that the calculation results are in good agreement with those of experimental study.