Abstract:The Pinus koraiensis virgin forest in Xiaoxing'an Mountains was selected to study its rainfall redistribution effect via 97 rainfall events in a growing season.The following results were concluded: 1) the canopy(interception) of the Pinus koraiensis virgin forest amounted to 98.68mm,which was 19.61 percent of the total rainfall and 1.3 times of that in secondary Betula platyphylla forest.Compared with other forest type in China the ratio of the canopy interception of Pinus koraiensis virgin forest was in a middle level.2) the throughfall and stemflow of the Pinus koraiensis virgin forest was respectively 395.77?mm and 8.78?mm,equaling to 78.65% and 1.74% percent of rainfall and the former was lower and the later higher than the secondary Betual platyphylla forest.3) the cubic regression equations describing the relation between throughfall,stemflow and canopy interception of the Pinus koraiensis virgin forest and the rainfall in open field were fitted but a linear regression equation was fitted between the throughfall of Secondary Betual platyphylla forests and the open rainfall.In this paper,the factors influencing throughfall and stemflow were analyzed and selected,thus important references were provided to study the rainfall redistribution effect of coniferous and broad-leaved mixed forest.