The information on land cover at national scales is critical for addressing climate change, biodiversity conservation, ecosystem assessment and environmental modeling. The Volunteered Geographic Information derived from the GEO_WIKI and Degree-Confluence Project was used as referenced data. The category accuracy and the category confusion about FORM-GLC-agg 500m and MODIS COLLECTION5 were compared and the spatial distribution of FORM-GLC-agg's category accuracy was analyzed. The results show that:there is no significant difference on producer and user accuracy between FORM-GLC-agg and MODIS data. They both have a serious confusion between Forest/shrub, cropland/shrub, especially the grassland and bare land. The category accuracy has an uneven distribution, for example, its higher value mainly distributes in northwest and north China, and the lower value more mainly distributes in Tibet Plateau, and southwest China. The results can provide reference for land cover research.