The diversity of arbuscular endomycorrhizal fungi colonized on three species of Alnus at Changbai Mountain was identified based on coupling the sensitivity of semi-nested LP-PCR and the specificity afforded by Single Strand Conformation Polymorphism analysis. It is suggested that altitudes and species of Alnus were not the important factors deciding the distribution of AMF in the grade of family, and there was at least one species of Glomaceae, Glomus intraradix, dominated in Alnus at Changbai Mountain.