In order to study the aseismic behavior of a 170kV neutral reactor used in an UHV substation，one such reactor was tested with a seismic simulation shaking table. The dynamic characteristics of the reactor were obtained through inputting white noise and the standard time history waves. The acceleration, strain and displacement responses of its key positions under the action of earthquake waves with peak accelerations of 0.15g, 0.3g and 0.4g were obtained, respectively. Test results showed that the fundamental natural frequency of the reactor is 13.27Hz, and that of its high voltage bushing is 5.85Hz; the dynamic amplification factor  of the ascending flanged base of the high voltage bushing is larger than the code prescribed value; under the action of the standard time history waves with the designed basic acceleration of 0.4g, the maximum stress of the high voltage bushing, the neutral point bushing and connecting components of the oil storage tank meet the code requirements; the designed strength of the reactor’s main components meet the aseismic requirements under the designed basic seismic acceleration of 0.4g; displacements of the high voltage bushing and the oil storage tank are larger, the traction effects of displacements on conductors should be considered during design.