Abstract: The Late Ordovician carbonates in Wudang, Guiyang differ from the coeval sediments at other sections in Yangtze area. Based on the study of the Middle and Late Ordovician in Wudang, in combination with analysis on sedimentary facies, it is deduced that the Huanghuachong formation was formed in restricted subtidal environments. Five sedimentary facies have been distinguished, i.e. skeletal grainstone, skeletal packstone, skeletal wackestone, lime mudstone and shale-siltstone facies.