Intergenerational support between parents and children in Chinese cities has been dramatically affected by recent social changes. This paper investigates the changing pattern of intergenerational housing support between retired old parents and their children, and the legacy of public housing in shaping this pattern. By initially establishing an up-to-date picture of intergenerational housing support between retired old parents and their children, it seeks to determine how this support depends on whether parents have previously been allocated public housing and, if so, on whether they have disposed of it or have continued to occupy it. A survey with 1000 retired old people from Tianjin in 2009 is used for the analysis. A support flow model is used to go beyond studying housing support per se, and to study the flow of intergenerational support in both directions and in different forms.