An innumerable number of buildings in the coastal part of the east side of Japan were devastated by the Great East Japan Earthquake and Tsunami. Medical institutions also suffered the damage caused by tsunami, and the function to carry out the medical act has been spoiled. And the disabled concentrated on the medical institution which avoided tsunami damage. Under such circumstances, assistance from the water area began three days after the earthquake disaster, and much support supplies reached the stricken area. It was revealed that the support from the water area including the river was extremely effective against the stricken area. And then, the Tokyo Inland Earthquake disaster was assumed, floating medical support system (hereafter, Medi-Float) installed in the quay of Arakawa River in Tokyo was proposed. Medi-Float is movable; furthermore, it is built in the structural system of having very high isolation characteristics. The float proposed in this study is a facility based on a completely new concept and hence it is difficult to get approval as simply a hardware structure or facility, even if it is safe. Our study considers the constraints with respect to installing the system on the river as the basic plan of the specific Medi-Float. It takes into account the floor planning and flow planning based on operational methods, considers scale planning and weight calculation and the structural strength of the float foundation. The study conducts basic plan of the feasibility of the first-of-its-kind medical float as a marine structure. As the next step, the research on dynamic behavior of Medi-Float will be started, and the validity of this design is verified, technical issues in the design of the Medi-Float should be clarified.Copyright © 2015 by ASME