Abstract: On the basis of apparent elasticity method, we developed the equivalent circuit of coupling vibration of a short column. Using the equivalent circuit we calculated the input impedance and the apparent radial-to-longitudinal vibrating velocity ratio. The results show that the analyses and calculations of the short column can be simplified and rational designs of this kind of column as a radiator working in liquid medium can be attained our experiments indicate that the measured frequency agrees well with the designed one and the rationally designed short column is a kind of high power radiator in the liquid medium.