The spectroscopic properties of the FT-IR and FT-Raman spectra of the 2-［(2,3-dimethylphenyl)amino］benzoic acid (DMPABA) compound have been recorded in the region 4 000～400 cm-1. The molecular structure, vibrational wavenumbers were calculated using DFT (B3LYP) method with 6-31G(d,p) and 6-311++G(d,p) basis sets. The Geometrical structure, vibrational frequencies, corresponding vibrational assignments of 2-［(2,3-dimethylphenyl)amino］benzoic acid (DMPABA) have been investigated experimentally and theoretically using Gaussian03 software package. The detailed Molecular orbital calculation such as Natural Bond Orbitals (NBO), Natural Population Analysis (NPA) and Mulliken analysis of atomic charges is also calculated.