Ostryopsis davidiana is a special species in China, and is also advantagous shrub of Daqing Mountains weak ecological system; Cenococcum geophilum (Fr.) spread widly in the world and have strong adaptability. C.geophilum (Fr.) applied to experiments can be isolated from O.davidianas thin roots. It can be proved by seedling back-inoculation to O.davidiana that inoculated mycorrhizae infectious rate reaches to 67.2, and that formed mycorrhiza is the same as wild mycorrhiza. It was found that the typical sclerotium organs in seedling back-inoculation substrate. The experiments prove that C.geophilum(Fr.) has no obvious affect on O.davidianas overground parts, however, it has apparent promotion to growth of ground iameter and roots. Inoculation disposal root/shoot ratio is 2.18 times more than comparative disposal one. This may be the reason that O.davidiana can grow normally while other plants on Daqing Mountain become degraded and extinct.
