Abstract: As one of the 'three lines', which should be rigid control in the territorial planning system, the delimitation of urban development boundary has been explored but yet formed a unified method. Based on summarizing the previous policies and present methods, this paper put forward a multi-dimensional phase-based delineation method. From the perspective of resource bearing, development demand, morphology and flexibility, the delimitation was divided into four phases of initial planning, integration, optimization and checking. By taking Heshan City of Guangxi Zhuang Autonomous Region as an example , the proposed method not only effectively protects the ecological background, but also improves the agglomeration of urban land.