Detailed investigation of the distlibntions of the Hindeodus and Clarkina (Neogomlolella) conodont fannas has been 1ruder taken on the P/T bolmdary strata of the Meishan section, Zhejiang Province, Sonth China, in association with detailed facies mlalysis. This reveals that Hindeodus increased mid Clarkina shin-ply declined in ablmdmlce dltring a phase of relative sea level rise which begin at the end Permian (Bed 25) mid extended into Early Triassic. This was associated with the development of mmxic conditions. This distfibntion does not accord with previons snggestions that Hindeodus was a nearshore, shallow water taxon. The decline of the snpposed deeper water genus Clarkina is also somewhat Sltrprising bnt it may relate to the i111rihition of a nektobenthic genus by dysoxic anxic bottom waters. The widespread facies and geographic distfibntion of Himleodus suggests it was a pelagic type lmaffected by anoxic bottom waters. Hence, the Hindeodus lineage provides a reliable criterion for identification of the Peianian-Triassic bolmdary.