Abstract: The suspension stiffness and damping of an actively controlled electromagnetic suspension system were analyzed theoretically and numerically. The suspension unit consisting of single magnet and series suspension controller was taken as the object for analysis. The analytical results show that the suspension stiffness is positively proportional to the feedback coefficient of airgap and the suspension damping is positively proportional to the airgap derivative. Resonance may occur if any two of the characteristic frequencies of the secondary suspension, the guideway and the control system are close to each other.