Three typical manganese coatings, i.e., rock varnish, dendrite and soil iron-manganese cutan, were collected and corresponding thin sections were made for laboratory research. The authors utilized optical microscope, micro-Raman spectrometer, scanning electron microscope and energy dispersive X-ray detector to systematically study the micro morphological features, mineral assemblage and elements distribution of these three manganese coatings. The results suggest that rock varnish is dark layered or botryoid deposit which consists of birnessite, hematite, goethite, clay minerals, etc., indicating a highly-mixed coating. The boundary between rock varnish and substrate, and also the microlaminations which arise from the manganese content fluctuation within the sample profile, are obvious on closer inspection. Dendrite is black branch-like coating and mainly composed of hollandite-group minerals. Unlike rock varnish, dendrite, enriched in manganese and devoid of silicon and aluminum, shows pilotaxitic texture with its substrate. Soil iron-manganese cutan, a kind of black soft deposit, comprises birnessite, hematite, goethite, ilmenite, clay minerals, etc., and can be further divided into an outer black manganese-rich belt and inner yellowish-brown iron-rich belt. The micro morphological features of these manganese coatings, together with elements distribution, reveal intimate relationship with their formation mechanism.