Abstract: Constructing and optimizing ecological network of natural protected areas is beneficial for mitigating the isolation of natural protected areas and biodiversity conservation. Taking Hexi Corridor as an example, we identified the spatial distribution of wilderness areas. High quality wilderness areas and natural protected areas were consi-dered as ecological source areas. Using the minimum cost distance model and circuit theory to extract ecological corridors and important ecological nodes, we established a potential ecological network of natural protected areas and implement network optimization with two optimization scenarios: restoring barriers (scenario 1) and adding stepping stone nodes (scenario 2). The optimal solution was determined through a comprehensive evaluation of habitat connectivity and network stability. The natural protected areas in Hexi Corridor exhibited an ecological network pattern of “one main corridor, five secon-dary corridors, two horizontal connections, and multiple vertical connections”. Among these, Qilian Mountains National Park played a crucial role in maintaining the overall connectivity of natural reserve network, while the peripheral protected areas and natural parks had weaker functions in sustaining the connectivity of the entire network. A total of 65 ecological pinch points and 57 ecological barriers were identified. Both were primarily located in the western and eastern areas of the Hexi Corridor, with large expanse of desert. In the two optimization scenarios, the number of source areas and corridors increased to varying degrees, and there was an improvement in network closure, point-to-line ratio, and network connectivity. The robustness under deliberate and random attack patterns showed a varying degree of decline. In scenario one, the ecological network exhibited better buffering capabilities and stronger stability, indicating that the optimization strategy of restoring barriers to facilitate potential corridor connectivity was the most effective in enhancing the connectivity and stability of the protected area network. Constructing an ecological network for natural protected areas and proposing optimization strategies can address issues, such as the isolation of natural protected areas. This could provide scientific support for maintaining biodiversity and promoting sustainable development in Hexi Corridor, and serve as a reference for natural reserve planning and ecological restoration planning in national territory.

Key words: nature reserve, ecological network, circuit theory, wilderness area, Hexi Corridor, robustness