Two pot experiments were conducted at the nursery of the Ornamental Horticulture, Department, Horticulture Research Institute, A.R.C, Giza, Egypt. to study the effect of different Bio fertilizers (Azotobacter chroococcum, Bacillus circulans and Arbuscular mycorrhizal fungi AMF) and soil media (sand, sand:caly and clay) and their interactions on growth, chemical compositions, microbiological parameters and enzymatic activity in rhizosphere of the river red gum (Eucalyptus camaldulensis Dehnh) seedlings during two consecutive seasons of 2011 and 2012. The results in both seasons pointed out that the mixture of Azotobacter chroococcum, Bacillus circulans and Arbuscular mycorrhizal fungi (AMF) and/or clay and sand+clay significantly increased plant height, stem diameter, number of leaves, leaf area, fresh and dry weights of shoots and roots, chlorophyll a,and b, total carbohydrates, N, P, K% compared with the seedlings grown in sand medium and un-incoulated control. Also the results revealed that this treatment was recorded increase of total microbial count, Azotobacter chroococcum count and Bacillus circulans count. The highest significant increase in percentages of colonization of AM fungi (%), enzyme activity (dehydrogenase and nitrogenase), percentage of organic carbon and organic matter were recorded in the treatment inoculated with the mixed microbial treatment rather than that of individual and dual treatments in two seasons.