Beijing is one of rapid urbanization city in the world. The population is about 20,693,000 which is 26th largest population in the world, and 4th density in the world. A massive number of people flocked to the Beijing, they have implemented a household registration system. Most of residents were hard to find house because in the middle of Beijing's house is too expensive. So they desired government low rent housing. So it makes their quality of living becomes lower. Most of Beijing workers are working in downtown Beijing. But most of workers could not live in downtown Beijing, so they have to travel far distance everyday which makes horrible traffic and pressure on public transportation system.