Abstract: There occur ministromatolites at the top of Member H₈ of the Bayan Obo Group. They have the structural elements and features of deformationmetamorphism of folded stromatolites. The phenomenon of gradual transition from typical stromatolites to rheomorphic structure due to structural deformation may be observed in both macroscopic specimens and microscopic thin sections. This paver describes the changes and features of the above-mentioned ministromatolite after structural deformation. The authors consider that some "coral fossils" identified by predecessors are ministromatolites.