Abstract: According to the morphological and anatomical characteristics, the sampledmycorrhiza of Populus tomentosa from the central China are divided into 14types. Their anatomical characteristics indicate that most of them have a bador worse symbiotic relationship with the host plant. Statistical results from distri-bution characteristics index of the mycorrhiza show that the beneficial ectomy-corrhizal fungi exist rarely in the forest soil of Populus tomentosa. The majo-rity of them occur in the soils whose pH value are less than 7.5.On the con-trary the mycorrhiza with the bad or worse symbiotical relation or pseudom-ycorrhiza are dominant in the alkaline soils. In the alkaline nursery soils, onlya few of the ectomycorrhizal types have been discovered in roots of the nur-sery stock and the pseudomycorrhiza, type 5, makes up the majority of them.The tree ages seem to have no effect on the mycorrhiza formation in Populus tomentosa plantation.

Key words: Populus tomentosa, Ectomycorrhizal type, Distribution characteristics index, Symbiotic relationship