Uing the ectomycorrhizae on Betula platyphylla in Inner Mongolia different areas as experimental material.The primary study on the diversity of ectomycorrhizas associated with B.platyphylla in Inner Mongolia area was investigated using morphological and anatomical and molecular method,then identification results were obtained according that the sequences were BLASTed using the GenBank and UNITE database.The results indicated that there are 13 different ECM fungi on B.platyphylla in Inner Mongolia area.Among the 13 identified ectomycorrhizal fungi,4 species belong to Ascomycotina and the rest species belong to Basidiomycotina,they belong to Cortinarius,Inocybe,Sebacina,Piloderma,Hebeloma and Cenococcum,Tuber,Geopyxis,respectively and among 13 different types,T₈ and T₁₁ failed to extract the DNA.So according to the map of ectomycorrhizal fungi which were built by Agerer and Haug,the two types were identified as Leccinum holopus and Betularhiza luteopinnata.The results shown that the diversity of ECM on B.platyphylla in Inner Mongolia area is higher,and it is different with the result which was identified by fruiting body associated with B.platyphylla.