A concept for a floating city With fast developing of the offshore and shipping industry, people are talking about next bold and exciting object, the floating city. and there are already many ideas and pictures on the internet , most of those concepts are brilliant, however not so practical as for marine engineering, particularly the shape of the floater is not suitable for the ocean, which is usually dominated by waves and currents. most possible shape for a big object in the sea is a small water-plane area floater, that means most part of the buoyant body is submerged, and only supporting columns visible at surface. in that way, big wave will not cause significant motions. Developing a floating city will roughly run several stages: Stage 1: Floating hull development. the designer shall focus on main issues like: payload estimation, hydrodynamic characters of the floater, mooring system, marine equipment requirement etc. Stage 2: City layout and architectural development, something like exploitation of a real estate. all those work will be carried out on the floating hull platform. Stage 3: Back check and refine. in stage 2, more information will feed back to stage 1, including building weight distribution, power, water and other utility requirements. designers will check and refine the design step by step, it may even overthrow the floating hull design and begin a new concept. Finally we will find the solution.