The composition of seven neutral monosaccharides (glucose, galactose, mannose, xylose, arabinose, fucose and rhamnose) released by acid hydrolysis with 0.5 mol L-1 H2SO4 was compared among four humus fractions, including humic acids (HAs), fulvic acids (FAs), water-soluble non-humic substances (WS-NHS; XAD-8-non-adsorbed fraction of the FA fraction) and humin, for two representative types of Japanese soils, an Umbric Andosol (ando soil) and a Dystric Cambisol (brown forest soil). Although more than 58% of the hexoses and pentoses in the soil were recovered in humin, 29-57% of fucose and rhamnose were found in WS-NHS. In the principal component analysis, humin was separated from the other three fractions because of larger proportions of glucose and xylose and smaller proportions of fucose and rhamnose. The HAs contained a larger proportion of arabinose than the other fractions. The monosaccharide composition of the FAs and WS-NHS was similar in each soil type. As deoxyhexoses and pentoses in soil are known to originate mainly from microorganisms and higher plants, respectively, the contribution of microorganism-derived saccharides to total neutral saccharides was considered to be greater in the order of WS-NHS and FAs > HAs > humin.