Urban development and industrialization cause many problems on urban environment such as climate changes, natural disasters and a decreasing number of species. Problems on urban environment are the main factor of that lower the quality of life and obstruct continual development. As a result, eco space becomes the important part of an urban planning. We suggest accretion with Ubiquitous (Ubiquitous will be Written “U-”) technology to three physical divisions, which are lithosphere (land), hydrosphere (water), and aerosphere (air), that interact with the whole biosphere by forming a u-eco space system. As examining U-Eco Space system from ecological aspect, green ecosystem and water ecosystem cannot be a perfect habitat only by themselves. U-Eco space system will be effectively function on the ecosystem When It have plan and design U-Eco space system with three elements U-Green belt, U-Blue belt, U-White belt. Ubiquitous technology will embody sustainable smart city with clean environment, health ecosystem and people convenience