The Beijing Urban Master Plan approved by the Chinese Central Government and the State Council, Beijing's population size should be controlled to within 23 million people by 2020, and after 2020 the population should be within this level for long-term stability. In 2020, urban and rural construction land should be reduced to about 2860 square kilometers, and in 2035 reduced to about 2760 square kilometers. Beijing should strictly adhere to the three "red lines" of total population limit, ecological control and urban development boundary. In addition, the old quarters cannot be demolished, and should be conserved as much as possible.