Abstract: The Yuhuashan rock body in Jiangxi is a high-level composite plutonic complex,which hascompositional and structual evolutiOnary sequences.From the viewpoint of comagmatic evolu-tion and using the method of lithodemic division,the complex can be divided into the Yaoli su-perunit,Mifengjie superunit,Yuhuashan superunit and Taoxi independent unit.On the basis ofan analysis of the fabrics,features of deformation,spatial distribution and regional structuralfeatures,this paper puts forward the mechanisms of cryptoexplosion dilation,dike dilation andcrater collapse for the emplacement of the complex.