Abstract: Arbuscular mycorrhizal (AM) fungi are one of the important components
of biodiversity in ecosystems. They are rich in species diversity, genetic diver
sity, and function diversity. Their taxonomy position moved forward to phylum, a
nd there are 214 species belonging to 19 genera, 13 families, 4 orders, and 1 cl
ass reported in the world. AM fungi play a vital role in keeping ecological bala
nce and enhancing ecosystem sustainable productivity. This paper reviewed the re
search advances in the species diversity of AM fungi distributed globally, the k
ey factors affecting this species diversity in various ecosystems, and related r
egulation pathways. It was considered that molecular biological techniques would
 be the main approaches in the future study of AM fungal species diversity.

Key words: arbuscular mycorrhizal fungi, species diversity, species richness, diversity index, dominant species, coalmine, subsidence waters, nitrogen, phosphorus, eutrophication.