In this article, the thermodynamic properties of Bi­2212, as a function of oxygen pressure and temperature vaviations, have been studied. The results showed that variation of lattice parameters are directly' a function of temperature and conversely function of oxygen content. The experiments were set up at room temperature to 820 and different oxygen pressure from 5, 10, 50, 100 and 500 mb. It was found that the crystal structure of the Bi-2212 is stable from room temperature up to 815 and oxygen pressure of 10 mb but at 820, it committed decomposition and its crystal structure completely ruined. It was found that as a result of decomposition of some of the elements of the compound does interact with quartz and put it in a fragile position.