Abstract: In this study,the suspected Pathogen of Anoectochilus roxburghii Southern blight was isolated by tissue separation and purified from samples with typical symptoms.Then the pathogen was identified by pathogenicity test,pathogen morphology and molecular biology methods.The results showed that the strain from southern blight infected Anoectochilus tissues collected from Fujian were isolated.Mycelium was white,velvet-like,close to the culture medium,radially extended to the surrounding containment and branches,colonies formed on the surface of sclerotia,sclerotia early white,then change to yellow,and finally was dark brown,spherical or irregular spherical,smooth and shiny surface.The isolated strain has pathogenicity to tested Anoectochilus.The pathogen was identified pathogenically,morphologically and molecularly.Based on these data,it can be confirmed that the pathogen was Sclerotium rolfsii Sacc.