Abstract: In the previous report we studied the FTIRspectra and normal coordinate analysis of dimethylformamide (DMF), an important solvent having many desirable properties. In order to understand the nature of interaction between DMFmolecules in the vapor, liquid and solution stales, we have taken the advantages of the high resolving power and sensitivity of FTIRand studied the spectra of liquid DMFin the temperature range between 20° to 120℃ at 5° intervals and the effect of concentration on the spectra of DMFin CCl₄ solution. It has been found that the liquid DMFexists in dimeric form through the formation of an unusual hydrogen bond between C-H…O, and in CCl₄ solution, equilibrium exists between the dimeric and monomeric forms of DMF, the position of equilibrium is dependent upon the concentration.