Compression work on a pyrite powder has been carried out using energy dispersive X-ray diffraction (EDXRD) with Mao-Bell type diamond anvil cell (DAC) and synchrotron radiation(SR) at room temperature. It has been reported the bulk moduli of pyrite show the large variations depending on the experimental conditions as well as the apparatus used. Thus, two kinds of sample in different pressure transmitting media of both NaCl and MgO powder emerged in alcoholic fluids were subjected to measure their compressibilities. Bulk moduli thus obtained are 138.9 GPa and 198.2 GPa, respectively, and this result contradicts to the anticipated values according to the hydrostaticity conditions of the sample chamber. This might be due to the alcoholic fluids phase transition mainly with the side effects from the difference of both solid state detector (SSD) used and E*d value applied. All experiments were performed at the Beam Line 1B2 of Pohang Light Source (PLS).