In order to thoroughly understand the mechanism between microbe and atmospheric inhaled mineral fine particles, the authors used calcite (PM_2.5) as the research object, and made qualitative and quantitative analysis of the main components of Silicate bacteria, Staphylococcus aureus and Escherichia coli extracellular organic acids by reverse phase high performance liquid chromatography (RP-HPLC). On such a basis, the authors investigated the dissolution of calcite by bacterial organic acids. The results are as follows: The main organic acids components of three common bacteria include oxalic acid, lactic acid, citric acid and succinic acid; Different organic acids have different effects on dissolution of calcite: ① Serveral different organic acids can promote the release of Ca ions at different levels; ② Calcite exhibits the weight of grain decrease under the action of oxalic acid, lactic acid and citric acid, whereas recrystallization occurs under the action of citric acid, which aslo can change the surface morphology of calcite, making the residue exhibit fibrous form; ③ Under the action of oxalic acid and citric acid, the residue absorbs the organic acid groups (e.g. C=O, C—C or C—H), especially in the region 1 600～500 cm^-1 in citric acid.