Abstract: Plant residues are the main component of peat and its mineral bodies. The composition of plants in the peat has close relations with the decomposition degree and the nutrition status of peat. The composition of plant residues is an important basis for making the classification of peat. The mineral bodies of peat in China are now tentatively divided into 11 groups of 4 types, which are classified according to the principle of taxonomy by the features of these mineral bodies and their qualitative differences, and on the basis of the components of the plant residues in the mineral layers.