【Objective】Aiming to address the problems of rapid expansion of urban construction spaces and the gradual loss and fragmentation of green spaces, an effective method for optimizing the urban green infrastructure (UGI) network system is explored to provide a more scientific city-scale reference for green infrastructure (GI) construction.【Method】Taking Nanjing city as an example, using the morphological spatial pattern analysis (MSPA) method, on the basis of the land use map, seven important landscape types are identified in the existing green spaces of Nanjing including cores, edges, islets, bridges, loop, perforation and branch, respectively. Through patch area calculations and connectivity index evaluations, green infrastructure network centers with ecological potential are identified, and the least cost path to generate potential corridors is calculated, combining existing core areas, potential nodes, existing corridors and potential corridors to construct the future green infrastructure network system in Nanjing.【Result】Using the MSPA method, the core area of Nanjing’s green infrastructure is 538.16 km², accounting for 37.57% of the total study area. A total of 16 first-level network centers and 24 second-level network centers were selected. A total of 73 ecological corridors are constructed based on the resistance model, which are densely distributed in the south of the Yangtze River with a higher importance level. There is a small number of ecological corridors in the north of the Yangtze River, and the importance level needs to be improved.【Conclusion】 The MSPA method can provide more accurate identification results of ecological characteristics for the construction of urban green infrastructure, since it has the characteristics of a small amount of data and easy visualization and it effectively enhance the system and structure of green infrastructure. According to the results of the construction of the green infrastructure system in Nanjing, strengthening the construction of network centers and corridors in the north of the Yangtze River is recommended, as well as to improve the quality of network centers and corridors in the south of the Yangtze River to advance the ecological function of the whole city.