Abstract: In the context of China's implementation of its carbon neutrality strategy, exploring territorial space zoning under the framework of low-carbon ecological development is the core of territorial space optimization. Yulong County in rocky desertification mountainous area was taken as the research area. Based on the analysis of land use changes, the carbon source and carbon sink in Yulong County in 2010 and 2020 were calculated and its spatial-temporal characteristics were analyzed, then comprehensive territorial space zones were divided for the coupling of carbon source/sink and ecology, and the differences of collaborative reduction countermeasures are put forward. The results showed that: (1)The land use structure of Yulong County from 2010 to 2020 was dominated by forest, shrub land, grassland, dry land, and build-up land increased the fastest. (2)The growth of carbon sources in Yulong County from 2010 to 2020 is dramatic, with carbon emissions rising by 74.96%, and the growth in carbon emissions far exceeding the growth in carbon sequestration. (3)The benefits of carbon sink in Yulong County increased greatly from 2010 to 2020, but there were still large areas with low benefits. Moreover, Yulong County was dominated by areas with high habitat quality. (4)According to the carbon source, carbon sink benefit and habitat quality, Yulong County was divided into six zones: carbon sink function zone, low carbon and limited development zone, reducing carbon source and priority to develop zone, ecological restoration area, high carbon production optimization zone and high carbon total control zone.