Recently, Chinese economic society is expanding by a very high speed to build a big business in the international trade being called as “factory in the world”. The society subsequently discharges a lot of pollutants of waste-water and waste-air causing an environmental degradation in the various local regions. A large volume of industrial and domestic waste-water discharged from the society should be digest artificially through the sewage system using an activated sludge process to construct environmentally concerned society forming a sustainable development. This paper deals with the sewage system in QingDao-city, China comparing with the system in Kure-City.