There are more than 2,800 counties in China, including 341 in the Loess Plateau region. The county is the basic unit of administrative management and is considered to be the best scale for land use control, environmental planning and policy implementation. Since the 1990 s, socioeconomic development and the implementation of ecological engineering have greatly changed the land use and land cover (LULC) patterns in the Loess Plateau counties, and presumably in the county’s carbon. However, accurate assessment of carbon storage and driving factors remains a challenge. This paper selected Qingcheng County, a typical county in the Loess Plateau, and used multi-source data and comprehensive environmental modeling methods to evaluate and analyze the temporal and spatial trends and driving factors of carbon storage in Qingcheng County from 2000 to 2030. The results showed that: (1) the carbon storage in the terrestrial ecosystem increased from 2000 to 2030 in Qingcheng, and it was mainly distributed in grassland and forest, accounting for 49 %–53 % and 36 %–40 % of the total carbon storage, respectively. (2) The implementation of ecological engineering had obvious promotion effect on carbon storage in the terrestrial ecosystem. The precipitation and temperature in the past 20 years had provided favorable climatic conditions for ecological engineering. In addition, carbon storage was also affected by economic development, land input intensity, and population size. These findings provide recommendations for achieving sustainable socioeconomic and ecological development at county-level. This study contributes to a deeper understanding of the relationship between LULC and carbon storage caused by natural environment and socioeconomic factors.