Two kinds of magnetorheological sandwich beam structures which were fabricated by magnetorheological fluid (MRF) and magnetorheological elastomer (MRE) materials were respectively designed . The test rig was set up to investigate the natural frequency and dynamic response characteristics of MRF sandwich beam and MRE sandwich beam under different magnetic field intensity and different external applied magnetic regions. The experimental results show that the natural frequencies of MRF and MRE sandwich beams decrease with the increasing of the external magnetic field intensity；when the magnets move from the fixed end to the free end, the natural frequencies of the MRF and MRE sandwich beam decrease, and the decline rate of MRE sandwich beam is larger than that of MRF sandwich beam.