THE PRESENT experiment was conducted in two successive ……seasons 2010/2011 and 2011/2012 to study the effect of Egyptian rock phosphate at the rates of 0, 115, 150 and 190kg/fed and inoculation with phosphate dissolving bacteria (Bacillus megaterium var. phosphaticum) on growth, fruit yield and oil yield of coriander (Coriandrum sativum L.) as well as the effect of these treatments on the activity of rhizospheric soil microorganisms of coriander plants. The results showed that coriander plants were significantly responded to Egyptian rock phosphate (ERP) and phosphate dissolving bacteria (PDB) solely or together. ERP and/or inoculation with PDB increased the vegetative growth expressed as plant height, number of branches, fresh and dry weights of aerial parts of plant. Also it significantly increased fruit yield. This increase was parallel to the gradual increase in the rate of Egyptian rock phosphate from 0 to 150 kg/fed. The interaction between ERP and PDB gave the highest fruit yield, oil percentage, oil yield, with the highest Linalool content.The inoculation with phosphate dissolving bacteria (PDB) significantly increased dehydrogenase enzyme activity of coriander plants, it has been as a valid biomarker to indicate changes in total microbial activity due to soil management and increased gradually with increasing the rate of ERP up to 150 kg/fed.