Abstract: The Sanjiang Plain region situated Jn the northeastern end of China is one of the concentrated distribution areas of mire in the country.This region has 11192 km of marsh,of which peat moor is 242km².Peat is a special product of mire.Plant residues are important components in peat.Plant residues provide the scientific basis for peat classification and utilization.Therefore, the study on plant residues has both production practice value and theoretical significane. The paper discusses peat distribution and emphasizes the main types and characteristics of plant residuesas,as well as the relationship between plant residues and peat.The plant composition and vegetation types of mires are closely related to plant residues.