The temperature dependencies of widths and frequencies of vibrational bands in MBBA (N-p-methoxybenzylidene p-n-butylaniline) corresponding to intramolecular vibrations (1100 - 1700 cm−1) were investigated in various thermal regimes. Regularities connecting frequencies and shape parameters with structural peculiarities of MBBA in different phases under fast and slow cooling were found. Besides it was obtained additional information about mechanisms of vibrational band formation in molecular spectra.