Abstract: There are several error sources in the spatial estimation process of regional aboveground forest carbon distribution, which directly impact the precision of the estimation results. This paper addressed the error sources by means of combining NFI plot data with Landsat Thematic Mapper images to estimate the regional aboveground forest carbon distribution. According to the uncertainty synthesis and distribution method to obtain the total error of spatial estimation and the proportions of various error sources which were quantified by the relative error. The error analyses on spatial estimation of regional aboveground forest carbon distribution based on 2004 NFI plot data and Landsat Thematic Mapper images from Lin′an Municipality, Zhejiang Province showed that the total error on spatial estimation of regional aboveground forest carbon distribution was 10.15% The proportions of each error were sampling error (63.5%), locating error of remote images coordination correction (229%), tree height measuring error (9.4%), biomass model error (3.4%) and DBH measurement error (0.8%).