Rhizoctonia is a soil-borne fungal pathogen which widely exists in the soil. This study, by comparing the two isolates of the AG-V which are new an stemsons group (AG)(Bs-J-06-7-1 and DL-YT-06-4-9), we find P absorption differences as well as their hyphae in the system P absorption rate interacting with three plants, and clear its specificity with plant interactions. Screening for the effect of hypo toxicity binucleate Rhizoctonias on promoting P absorption of three plants, the result is that there were significant differences on contribution rate of P absorption of fungus when two hypotoxicity Rhizoctonias interacted with corns in 40days, and the comparative results would be Bs-J-06-7-1>DL-YT-06-4-9, that when two hypo toxicity Rhizoctonias interacted with tomatoes in 40days, and the comparative results would be DL-YT-06-4-9> Bs-J-06-7-1, but when two hypo toxicity Rhizoctonias interacted with rapes in 45 days, and the comparative results would be Bs-J-06-7-1>DL-YT-06-4-9. Through comparative analysis of quantity and contribution rate of P absorption of fungus in this study, we found that the interaction of two hypotoxicity binucleate Rhizoctonias with corn, tomato and rape had some positive effect. But effect on P absorption tomatoes is not very obvious.