Abstract: The identification of magmatic flow that intruded into the metamorphic basement and the recognition of the differences between magmatic flow and metamorphic gneiss and mylonite along the ductile shear zones constitute important problems that should be reconsidered in modern petrology and structural geology. According to a comparative study of the features of magmatic flow from Daguangding pluton on the northern margin of the North China block and the relavant superimposed ductile shear deformation and metamorphic gneiss, in combination with the investigation of magmatic flow and solid-state flow, the authors identified magmatic flow which was formed in the cooling crystallization process from the metamorphic basement during the late magmatic emplacement period. This paper provides criteria for structures and microstructures produced by magmatic flow.