Abstract: The cultural conditions for the proliferation of a strain, SF-86902 selected from Pisolithas tinotorius (P.t),a species of symbiotic fungi with Masson Pine, have been studied. The results showed that under artificial pure-culture, the optimum growth temperature was 25℃; the optimum pH in the culture solution was 5.5; the sources of carbon and nitrogen which are easily absorbed and used were monosac glucose and inorganic ammonium nitrogen respectively. The research provided scientific basis for preparing mycorrhiza inoculum by the P.t fungus of ectotrophic mycorrhiza with Masson Pine.