Abstract:The research investigated the effects of the growth of clonal plants on the diversity of AM fungi and mycorrhizal formation over two years at two representative sites, OSES and RSCF, from north to south, in Mu Us sandland. The clonal plants were Psammochloa villosa and Hedysarum leave. The results showed that the ability of clonal plants to increase the diversity of AM fungi and mycorrhizal formation differ between plant species and sampling sites. After P. villosa invasion, the Shannon-Weiner index of AM fungi rose in both sampling sites. Additionally, the spore density level, the colonization rate of hyphae and arbuscules, the total colonization rate and colonization rate of vesicles all significantly increased. After H. leave invasion, the Shannon-Weiner index of AM fungi rose in OSES but descended in RSCF. At both sites, the spore density and colonization rate of arbuscules significantly increased and, at each, the colonization rate of vesicles rose to a maximum then declined. At OSES the hyphae and total colonization rate rose to a maximum and remained but at RSCF these values declined significantly after peaking.