Abstract: Objective To study organic acid secreted from phosphorus-solubilizing bacteria and calcium phosphate dissolving ability.Method The P7,P13,P15 and P18 phosphate-solubilizing bacteria were sent to cultivate for dynamic observation.The organic acid types and content were determined by high performance liquid chromatography (HPLC) method for studying the relationship between phosphate-solubilizing and organic acids.Result The research showed that dissolving calcium phosphate capacity of the 4 strains of bacteria had significant difference,the order of which was:P15 ＞ P13 ＞ P18 ＞ P7 and the content difference of four kinds of bacteria producing organic acids was also great,and organic acids produced by the same bacteria at different times were different,too.Through the path analysis,it was found that the direct effects of organic acids on available phosphorus in descending order were:pyruvic acid ＞ tartaric acid ＞ lactic acid ＞acetic acid ＞ oxalic acid.Conclusion The strongest ability to solve phosphorus bacteria is the P15 strain and the direct influence coefficient of pyruvic acid on the dissolution of calcium phosphate is the largest.