Abstract: Ecological network can connect fragmented habitat patches to increase the connectivity among landscapes, which plays an important role to landscapes and ecological problems caused by urbanization. In this study, the ecological networks of Xi'an City were constructed using landscape pattern index and morphological spatial pattern analysis to reveal landscape pattern features. The performance of the network was evaluated with the gravity model to provide an optimization strategy. The landscape richness index was relatively high, with significant differences of landscape patterns between north and south parts. The ecological sources were predominated in the south and east areas, while a higher comprehensive resistance with low connectivity was found in the north and central areas. The ecological corridors were unevenly distributed, with the radiation channels derived from hydrological analysis providing a supplementary role. Furthermore, ecological networks could be optimized by introducing other ecological sources, supplementing stepping stones, and repairing fracture points, to reduce the problems of uneven distribution of ecological sources, the excessively long ecological corridors in local regions, and the obstruction of road networks. Our optimization method provided an optional way to assist urban planning of Xi'an City.

Key words: ecological network, landscape pattern index, morphological spatial pattern analysis, gravity model, radiation channels