Abstract:Based on highprecision online atmospheric CO2 concentration measurements from the Shenyang Urban Ecological Station from June 2023 to May 2024, the REBS （robust extraction of baseline signal） algorithm is employed to separate regional background and pollution data. The influence of regional transport on atmospheric CO2 concentrations in Shenyang is analyzed using surface wind field data and MeteoInfo statistical software. The contributions of fossil fuel combustion emissions and ecosystem emissions/absorption to CO2 concentration are estimated according to carbon conservation principles. The results show that the average CO2 concentration at Shenyang Urban Ecological Station is 477.2×10-6, with background and pollution concentrations averaged to be 474.9×10-6 and 519.4×10-6, respectively. Highconcentration CO2 air masses affecting Shenyang originate from the southwest in spring and summer, and from northwest and southwest in winter. The potential CO2 emission source regions throughout the year are mainly distributed in most parts of Liaoning and Jilin provinces, southern Heilongjiang, eastern Inner Mongolia, BeijingTianjinHebei Region, Shandong Peninsula, and the Yellow Sea and Bohai Sea areas. Compared to fossil fuel combustion emission in other seasons, the fossil fuel combustion emission contributes more significantly to the atmospheric CO2 concentration in Shenyang during autumn and winter.