Abstract: We have done a series of experiments on the biological relationship of G. elata and Armillaria mellea (Vahl ex Fr.) Quel on the basis of popular experience. The results obtained are as follows: 1. The whole ontogenetic pattern of G. elata may be generally divided into four stages: seedling formation, tuber formation, flowering and fruiting. Except for the flowering and fruiting stage, the activity of Amella determines the formation of G. clara seedlings, the renewal of its vegetative organs, and transformation of vegetative growth to reproductive growth. The germination of tile dormant buds and their development are also decided by the sites and the influence of infection of A mellea . In some cases, when the mixed bud of G. elara was injured, it could also form several tubers with the infection of A. mellea . 2. The infecting process of A. mellea on G. elata has been studied in detail. Some of our observations are not well fitted with Kusano's experimental results. We find that there are two modes of infection of A. mellea on G. clara: physiological infection and pathological infection. Under normal environmental conditions, A. mellea infects the tissues of cortical layer only, and may also lead to the enlargment and malformation of nuclei. On the other hand; the digestive cells possess both the functions of defense and infecting hyphae. The pathological infection often exists under unfavorable conditions. 3. The tuber of G. data is not the only organ to assimilate the A. mellea, the vegetative stem also has a function of assimilation. 4. The growihg tuber would not become an assimilating organ until winter was over.