A total of 40 soils samples of different soil types from all over the country were analyzed for total N,organic matter,fixed ammonium,remaining organic matter (OM in the soil after treatment with KBOr),and residual organic matter (OM in the soil after treatment with KBOr-HF).Results show that in soils containing 2:1 clay minerals,residual organic matter is closely related to fixed ammonium in soil at an extremely significant level (r=0.831^**),and the organic matter existing in lattice is at a significant level (r=0.832^**),while in soils containing 1:1 clay minerals neither residual organic matter or lattice organic matter are related to fixed ammonium.The mean content of the remaining organic matter and residual organic matter in the 40 soils samples was 2.59 g kg-1and 3.70 g kg-1,accounting for 10% and 16%,respectively of the organic matter in the soils.