Vegetation or land cover maps have been made directly or indirectly available for the entire territory of China. The certainties anduncertainties of land cover statistics were analyzed by comparing three data sources: Chinas Vegetation Map, IGPB DISCover, and Universityof Maryland Product. Great similarities in the statistics of 7 aggregated land cover types were found among the three data sources, particularlybetween the two global land cover maps. The per-pixel agreement between any 2 of 3 maps was between 38.0%-51.4%; the per-pixelagreement among all three maps was only 27.1%. Certainties were found in regions where vegetation types are typical and human land usepractice is relatively homogenous; the uncertainties occurred to either vegetation transition zones or regions where land cover types and land usepractice are relatively diversified. Systematic and multidisciplinary efforts are necessary to promote accurate mapping of nationwide land covertypes in China. Intensive efforts should be made in regions where uncertainties of land cover information are found.