Abstract: The influencing factors of the enthalpy variation during adsorption processes of Acidithiobacillus ferrooxidans ATCC23270 on the surface of sulfide minerals and the metabolic thermogenesis of the bacteria under different conditions (different concentrations of the bacteria, different initial pH values and different media) were studied using microcalorimetry. The results show that the concentration of pulp at 0.03 g/mL and concentration of bacteria at 1.7×108 were the best environment for enthalpy variation during adsorption processes of A. ferrooxidans ATCC23270 on the surface of minerals. A. ferrooxidans cultured in different media with different contents of extracellular polymers (EPS) create different heat of reaction attaching on the surface of minerals. Bacteria cultured with pyrite having the highest EPS create the biggest heat of reaction, which proves the important role of EPS in the process of adsorption. The growth thermograms of bacteria can be determined by using the mircocalorimetric method. These perfect thermogram curves reflect the changes of bacteriaI growth patterns. For A. ferrooxidans ATCC23270, the best condition for the metabolic thermogenesis is at pH = 2.0 or 2.3, and concentration of bacteria at 3.0 × 108 cell/ mL. The bacteria cultured in different media create different growth thermograms. Media of 2039+ FeSO4 is the best one for metabolic thermogenesis.