There is an interaction between the root fungal community and the plant disease.In order to uncover the interaction between the pine wilt disease and fungal community in the root of pine tree,we investigated the activity of root tips,the colonization rates of ectomycorrhizal fungi(ECMF) and dark septate endophytes(DSE),and analyzed the root fungal community structures and diversities of Pinus tabuliformis in the pine wilt disease damaged and undamaged areas through the isolation and identification of culturable fungi.The results showed that:(1)Not only the ratio of active root tips and ectomycorrhizal tips,but also the colonization rate of ECMF were significantly higher in pine wilt disease undamaged area than those in damaged area(P<0.05),while the colonization rate of DSE and the density of microsclerotium were lower than damaged area.The colonization rates of ECMF were significantly higher(P<0.05) than those of DSE in both of the two sample areas.(2)Based on the morphological and molecular characteristics of 131 isolates,they were finally identified as 23 species,in which,the dominant fungi were DSE,especially Phialocephala fortinii and Cryptosporiopsis ericae.(3)The two sample areas only shared 5 species,exhibited obvious difference in root fungal community structure and diversity.(4)In the pine wilt disease undamaged area,the richness(17) and Shannon-Wiener biodiversity index(2.012 0) of root fungal community,as well as the relative abundance of ECMF(8%) were higher than those in damaged area(11,1.197 9 and 1.6%,respectively),but the relative abundance of DSE(70%) was lower than that in damaged area(82.7%).Above all,it is suggested that the outbreak of pine wilt disease affected the root activity,ectomycorrhizal development,colonization of ECMF and DSE,as well as the fungal community structure and diversity.This is the first report about the relationship between DSE and pine wilt disease.Further research is required to make clear the influence of these isolates on the resistance of pine tree against pine wilt disease.