The relationship between the hydrogen bond (H-bond) interactions and the formation of the cholesteric liquid crystalline phase was studied by Fourier transform infrared spectroscopy (FTIR), refractometry and polarizing microscopy, It was quite evident that the H-bonding played an important role in the early stage of the formation of cholesteric liquid crystalline phase in hydroxyethyl cellulose acetate (HECA)/dimethyl sulfoxide (DMSO) solutions and the rigidity of the HECA chains was more important to form liquid crystalline phase than molecular interactions when the concentration is very high.