Four bacterial and 8 fungal isolates were incubated in media for 6 days. It was found that organic acid content in the media increased largely, but pH decreased sharply. Phosphorus content in the media enhanced dramatically as well. The fungal isolates showed stronger ability to dissolve phosphate rock than the bacterial ones. These isolates excreted not only quite distinct volume of organic acids but diverse organic acid chemicals. The fungi produced more kinds of organic acids than the bacteria. However, there was no significant relationship between the total quantity of organic acids and P content in the media.