In this paper, nitration of 2,2'-diphenic acid was studied and two aromatic carboxylic acids containing two and four nitro groups, respectively, were synthesized and characterized through elemental analysis, IR spectra, respectively. Crystal structure of 4,4'-dinitro-2,2'-diphenic acid and 4,4',6,6'-tetranitro-2,2'-diphenic acid was determined by X-ray single crystal diffraction and their thermal decomposition have been carried out through differential scanning calorimeter analyses at a heating rate of 10 degrees C/min. The results indicate that the compounds have high heat-resistant stability.