Abstract: The Fangshan pluton developed some special “bending” phenomena, which are different from the wave-like patterns of normal linear or planar flow structures.These “folds” display a single-layer structure or disharmonic multilayered structure.In this contribution, we investigated theirmorphology and occurrence detailedly.On the one hand, by combining regional geological background and the adjacent field geological structures, we would like to ascertain their relationship with regional tectonic movement and later emplacement of magmas from the macroscopic view.On the other hand, based on the comparison of mineral compositions between the “folds” and country rocks, microscopic “deformation” analysis and simple “strain” measurements, we proposed three hypotheses on the genesis of these special “folds”.They include magmatic composition shift driven by volatiles, soret effect under the condition of gravitational convection and imperfect mixing between minor mafic liquid and host granitic magma.