Abstract: The southeastern part of yunnan province is one of the bases where Cunninghamia lanceolata are planted,and Maguan county is the centre of the base.Planting Cunninghamia lanceolata forests were being conducted often on the basis of changing primary vegetations.Therefore characteristics and sites of primary vegetations affect culture,growth and development of Cunninghamia lanceolata forests.This article referred to 10 forest types and 11 no-forest types(shrub forests and herbosas).In complince with viewpoint of plant ecology,the author analysed plant specieses,constructures and ecological characteristics of these vegetational types,at the same time a comparetion between the researched vegetation and Cunninghamia lanceolata forests has been made.The author arranged virtical distribution series and ecological series of some major vegetation types in the southeastern part of yunnan.From among two serieses position of Cunninghamia lanceolata forests were emphasized,and all the more affirmed relationship between it and other vegetation types.The study will provide useful references for culture,silviculture and mangement of Cunninghamia lanceolata forests.