Abstract: Using microcalorimetric method, we have determined the metabolic output power of Mouse Mammary Adenocarcinoma cell (MA 782/5S-8101) at the culture medium, the average value is 35.1 pW/cell. As cross reference, using the same method the output power of this cancer cell was determined at medium which contain inhibitor, the results show clearly that the output power was inhibited obviously, the correspondent average value is 23,2pW/cell.