In order to establish a global mitigation target, we must first quantitatively understand the budget of global carbon to support the mitigation policy. Here we simulated global CO2 distribution to estimate individual sources/sinks contributions. The chemical transport model was used to simulate global CO2 distributions with updated global sources/sinks inventories. The model simulated CO2 amounts were compared with recent satellite CO2 measurements(GOSAT)since 2009. The seasonal cycles of CO2 concentration were compared, and a systemic positive bias in the modeled data(~1%) were found with a fairly good spatial correlation(R2>0.6). In addition, the modeled CO2 have fairly good correlation with the ground measurements from WDCGG (World Data Center for Greenhouse Gases). We estimated the source/sink contributions to global atmospheric CO2 budget using a tagged simulation technique, and fossil fuel combustion is the main driving force of the current atmospheric CO2 trend(~2 ppmv/yr). We further downscaled the atmospheric CO2 budget over East Asia with a regional 3-D transport model, and we found that the continental carbon sources/sinks mainly controls the seasonal distribution of CO2 over the Korean peninsula. These study can be useful to support the regional low-carbon policy with a scientific information over East Asia in the 21st century.