A Very Large Floating Structure (VLFS) is expected as a new institution on the ocean. Rigidity of VLFS is, however, relatively small, so we cannot disregard an hydroelastic response of VLFS in waves. Many researchers studied about the elastic response of a pontoon type VLFS, and now we have knowledge about it. In addition, recent studies of column support type VLFS are progressing. The VLFS supported by columns shows the smaller elastic response than that of the pontoon type VLFS. Especially a column with footing has a wave-free frequency on wave exciting force, so we hope more restraining effects on the elastic response. Thus, we investigated on the hydroelastic responses of VLFS supported by footing-columns. In the analyses, the hydrodynamic forces of the single column are calculated by using 3-dimensional source sink method, and the hydrodynamic characteristics of VLFS are obtained by using hydro interaction theory. Then we discuss about the characteristics of the hydroelastic responses of VLFS in this paper.