Abstract: The growing conflicts between urban development and hydro-ecological system is a crucial issue. Building hydro-ecological security pattern (HESP) is an important planning method to protect the completion, health, stability of hydro-ecosystem and promote urban sustainable development. The existing HESP are mainly established based on the characteristics of hydro-ecology system, however, limited study is able to make the HESP by concerning the impacts of urban expansion on hydro-ecology system. This paper, taking Tianjin as an example, aims to explore an optimized method to identify HESP with land use change modeling. The results show that there are 8 lakes or wetlands, 11 main sections of river and many narrow rivers and streams are the sensitive area of urban expansion. The highly protected area in optimized HESP increased 809 km2. These findings indicate that land use change modeling can support identifying and optimizing the HESP.