Yunmengshan Formation, belonging to Mesoproterozoic Ruyang Group, lies in the southern margin of North China Platform and consists mainly of silicic clastic sedimentary successions. Microbially Induced Sedimentary Structures (MISS) occur on the surface of purple or yellow sandstone interbedded with mudstone or siltstone, especially on junction surface between sandstone and mud lamination. In the further investigation of thin-sections, five types of microstructures have been found: wavy crinkled laminae, network fabrics, mat layer bound small grains, mat layer bound heavy minerals and oriented grains. Microstructures could be used to reconstruct small-scaled facies within coastal environments.