///This paper presents the magnetic fabric of Bayankala Group sedimentary rocks in the Yellow River source area. It is shown that the rock magnetic susceptibility anisotropy (P value)and the percentage of anisotropy of magnetic susceptibility(H value)are not large either, suggesting overall weak ductile deformation in the area and strong ductile deformation in some parts. Based on an analysis of rock magnetic fabric, the authors found that there are two ductile shear zones in the source area of the Yellow River. The ductile shear zones and the current distribution of lakes have certain coupling relationship. The northern ductile shear zone along the present Yellow River valley dominates the distribution of Zhalinghu, Elinghu and “Four Sister Lakes” in Maduo. The southern ductile shear zone along Gangnagema Co-Yeniugou belt controls the distribution of remnant lakes.