Terrestrial ecosystems of the northern high-latitude region are thought to have been important sinks of atmospheric CO2, but some studies suggested that their absorption is decreasing in this century. To investigate carbon fluxes from northern high-latitude ter-restrial areas and their recent trends, regional CO2 fluxes are estimated by TransCom synthesis inversion method. The sum of inversed CO2 fluxes from the boreal Asia region and the boreal North America region showed decreasing (i.e. absorption is increasing) in this century. The result was compared with the inversed fluxes of CarbonTracker 2013 (CT2013). The sum of CT2013 CO2 fluxes from the boreal Asia region and the boreal North America region also showed decreasing in this century, but the signs of the trends of the fluxes from the two regions were opposite to those of this study.