Abstract: A large scale structure might have a very low first natural frequency, as low as 0.1 Hz. Traditionally, the method of the low stiffness suspension is a standard method for the modal test of structures. A requirement on the suspension stiffness is that the suspension frequency should be much lower than the first flexible natural frequency of the tested structure. For the large scale structure, a very long suspension spring is required to achieve the required frequency. This low frequency requirement might not be able to be met in many labs. In this paper, a method is proposed to deal with the above problem by replacing the low stiffness suspension with a group of supports that can have any stiffness. By removing the influence of the support stiffness from the computation with the measured frequency responses, the structure’s real modal parameters can be obtained conveniently. Experimental examples are given.