Abstract: After the disintegration of the “public rental housing allocation system” under the planned economy system, China has gradually built a new housing policy system which regulates the free housing market on the one hand and provides affordable housing on the other. It has been an important issue in the institutional construction and theoretical study to what extent the state has the obligation to provide housing security under legal restrictions. This paper analyses two levels of the national obligation on housing security with legal concepts “basic life” and “basic housing need”, maintaining that the security of basic housing need should be strictly restricted by laws and the constitution, while the security of those beyond basic housing need should respect administrational discretion, which should be based on improved democratic elements in policy making.