An experimental shake table study for the response of structures supported on base isolation systems under harmonic excitation is carried out. Two base isolation systems, namely the laminated rubber bearings with steel plates and sliding bearing, are designed and fabricated. These bearings are tested for their dynamic properties which are used for the design of the isolated structural models of single and twostorey steel frame structures. Experimental shake table studies of these isolated structural models subjected to harmonic base excitation are carried out. The response of the isolated structural system is compared with the corresponding response of non-isolated system in order to investigate the effectiveness of the isolation system. The experimental results are compared with the analytical results to verify the mathematical force-deformation behaviour of the isolation system. There was a good agreement between the experimental and analytical response of the structural models. In addition, the response of isolated system is found to be less in comparison to the corresponding response without isolation system, implying that the isolation is quite effective in reducing the acceleration response of the systems. The presence of restoring force device along with the sliding system reduces the base displacement without significant increase in superstructure acceleration. In addition, the response of the structural models has also been investigated for a real earthquake ground motion and it has been found that the isolation devices are effective in reducing the seismic response of structures.