In recent years,urban rail transit has sprung up rapidly in China and become an important part of the urban public transportation system.The extensive construction of urban rail transit has greatly enhanced the accessibility of the surrounding areas,driving the rising land rents along the line.This phenomenon has led to rising house prices along the urban rail transit line,which exacerbated the housing issue of low-income urban residents.In order to respond to housing demand for low-income residents,the public rental housing policy came into being.However,the preset location of public rental housing constructed by the government is usually in the suburbs,separating the workplace and residence for low-income residents choosing public rental housing,which greatly increases in commuting distance and commuting cost.Consequently,combined with transportation and housing,it is particularly necessary to study the effect of public rental housing policy on heterogeneous residents’ residential location choice from the perspective of urban rail transit travel.Based on the interaction between transportation and housing,the main contents of this paper are as follows:(1)From the view of individual choice of residents,this paper studies heterogeneous residents’ residential location choice based on the consumer equilibrium theory and the bid rent theory.Considering related factors such as income budget and commuting cost,a residential location choice model for residents based on urban rail transit travel under public rental housing policy is constructed.The interaction among the government,property developers,and heterogeneous residents in the urban system is considered and the effect of urban rail transit fares on the bid behavior of heterogeneous residents and the urban residential formation is analyzed.The result shows that the change in urban rail transit fares can affect the heterogeneous’ residential location choice and lead to the difference in urban residential formation and urban boundary.(2)As the manager of urban system,the government should maximize social welfare in order to promote the joint development of urban rail transit and public rental housing.On this basis,from the point of the government,this paper takes into consideration the constraints of government capital and urban development boundaries,and establishes the social welfare optimization model under the effect of urban rail transit fares and the number of public rental housing.The changes of heterogeneous residents’ residential location choice and social welfare under different population sizes and urban residential formations were compared.The result shows that no matter how the urban residential formation changes,residents always maximize their own utilities by choosing their residential location,and the optimal social welfare always exists.Based on the above study,this paper further finds that whether from the perspective of maximizing individual utility or maximizing social welfare,large-scale public rental housing may be detrimental if urban rail transit travel is considered.It provides the corresponding theoretical support for the government to make the sensible plan for the construction of public rental housing along the urban rail transit line.