Different P-solubilizing microbes can live in media containing different phosphorous sources. The author compared four strains, namely P17, Y3, F4, and P10, in phosphorus-dissolving mechanism and phosphorus-solubilizing ability. Results show that bacteria, fungus, and yeast play important roles in phosphorus-solubilization. Such artificial phosphates as aluminum phosphate, iron phosphate, calcium phosphates can be dissolved by yeast and mildew easily. Strain Phosphobacteria P17 (Bacillus megaterium) could dissolve phosphorus from phosphate rock powder from Huangmailing of Hubei Province easily;while yeast Y3 could improve solubility of calcium phosphate the most significantly among the four strains examined. They demonstrated different predominance in solubilizing phosphorus. The results also show that different strains of P-dissolving microbes can accelerate solubilization of phosphorus to a varying extent, which reveals that different chemical bonds have different effects on solubilization of phsphates and phosphate rock powder varied in solubility. Acids, acid phosphatase, and alkaline phosphatase have synergic effects on phosphate dissolution. Phosphatase could utilize substrates containing such organic phosphates as calcium phosphate, and Strain phospobacteria P10 produced the highest phosphatase activity among the four strains. Activities of acid phosphatase and alkaline phosphatase vary with P-solubilizing microbes. When growing in medium containing NH₄H₂PO₄, and KH₂PO₄ as phosphorus sources, activities of acid phosphatase and alkaline phosphatase with Strain phosphobacteria P17, Strain phosphobacteria P10, Strain yeast Y3, and mildew F4 were low. Activities of acid phosphatase and alkaline phosphatase were high in medium containing such hard-to-dissolve phosphates as calcium phosphate, aluminium phosphate, iron phosphate. The results show that in conditions short of phosphorus, acid, acid phosphatase and alkaline phosphatase help phosphorus-solubilizing microorganisms dissolve phosphorus more easily.