Nitration of 4,4’-biphenyldicarboxylic acid(BPDC) was studied and an aromatic carboxylic acid containing four nitro groups was synthesized and characterized through elemental analysis and IR spectra.Crystal structure of TNBPDC(TNBPDC = 2,2’,6,6’-tetranitro-4,4’-biphenyl dicarboxylic acid) was determined by X-ray single-crystal diffraction.The title compound(C20H20N6O14,Mr = 600.42) crystallizes in tetragonal,space group I41/a with a = 9.8774(1),b = 9.8774(1),c = 25.335(7) ,V = 2471.7(8) 3,Z = 4,Dc = 1.613 g/cm3,F(000) = 1240,μ(MoKα) = 0.142 mm-1,T = 294(2) K,the final R = 0.0797 and wR = 0.2177 for 554 observed reflections with I > 2σ(I).In this crystal,there exist a number of H-bonds which link the molecules to form a three-dimensional infinite network structure.The thermal decomposition of the title compound has been carried out through DSC and TG-DTG analyses at a heating rate of 10 ℃/min.The results indicate that the compound has high heat-resistant stability. Nitration of 4,4’-biphenyldicarboxylic acid (BPDC) was studied and an aromatic carboxylic acid containing four nitro groups was synthesized and characterized through elemental analysis and IR spectra. Crystal structure of TNBPDC (TNBPDC = 2,2 ’, 6,6’ -tetranitro-4,4’-biphenyl dicarboxylic acid was determined by X-ray single-crystal diffraction. The title compound (C20H20N6O14, Mr = 600.42) crystallizes in tetragonal space group I41 / a with 9.8774 b = 9.8774 (1), c = 25.335 (7) , V = 2471.7 (8) 3, Z = 4, Dc = 1.613 g / cm3, F (000) = 1240 and μ (MoKα) = 0.142 mm- 1, T = 294 (2) K, the final R = 0.0797 and wR = 0.2177 for 554 observed reflections with I> 2σ (I) .In this crystal, there exists a number of H-bonds which link the molecules to form a three-dimensional infinite network structure. The thermal decomposition of the title compound has been carried out through DSC and TG-DTG analyzes at a heating rate of 10 ° C / min. The results indicate that the compound has high heat-resistant stability.