The Raman and infrared (IR) spectra of dimethylformamide (DMF) containing different amounts of lithium perchlorate have been recorded and analyzed, respectively. It has been found that the Li+ ions interact with both the nitrogen atom in the quaternary ammonium structure and the oxygen atom in the C=O group of DMF. The activation of the IR-forbidden nu(1) mode and the splitting of the nu(4) mode of ClO4- anions indicate that ion aggregates are formed at low LiClO4 concentration. The results of the IR spectroscopic measurements also suggest that the ionic aggregation in the LiClO4-DMF system may have its own characteristics.