Abstract: An investigation on weed species biodiversity and host plants of vesicular arbuscular mycorrhiza fungi (VAMF) within weed communities in new developed f ruit gardens was conducted. Phosphorus content in various weed rhizospheric soils was analysed. There were 96 species belonging to 27 families in the weed community ,among which 39 species were tested to identify VAMF colonies. It was found that all the species tested were colonized by VAMF , but the percentage of colonization and the colonizing intensity were very different among the families and species. Correlation analyses showed that no significant correlation exists between phosphorus content in rhizospheric soil and VAMF colonization. VAMF colonization mainly depends on the characteristics of host plants and the selection of VAMF. This suggests that conservation of weed diversity in upland ecosystems will be favorable for conserving VAMF activities and diversity.