This chapter focuses on the policy evolution process of China's housing security system since the housing reform in 1994. Through a review, this chapter reaches several conclusions: (a) The housing security system has always lacked an overall planning from the very beginning. Its construction has been carried out in a loose organizational manner; (b) Providing affordable housing for middle and low-income groups is not the only goal of this system, nor even the most important one; (c) In the long-term practice, the experience of building this system has not been institutionalized; (d) The government has not handled the relationship between the commodity housing market and the affordable housing sector properly. This chapter argues that establishing an effective housing security system requires addressing several issues: Firstly, it is necessary to clearly define the position and functions of the system; secondly, to establish binding planning and institutions for this system; thirdly, to reasonably allocate the responsibilities of the central and local governments when building the system.