Abstract: By means of CNDO/2 and ab initio(STO - 2G) methods, we have calcula-ted the energies of systems R-N ≡ C…H-O-R'. The results of calculation confirm the formation of rather strong hydrogen bonds between isonitriles and hydroxyl compounds, as indicated by experimental evidences. The calculated hydrogen bond energies vary with the same tend as the red shift of IRspectra of the OHbonds. The relative stability of the Hbond formed by isonitrile and nitrile is also discussed.