On the basis of a simple MO-approach a model to interprete the IR-absorption intensity of the aromatic CH-stretching vibration is developed. Accordingly the gradient of the CH-bond moment is a linear function of the ionicity of the CH-bond. Eight azulenes, which were deuterated at various specified positions, were synthetisized and out of their IR-spectra the gradients of the CH-bond moment at all positions of azulene could be determined. From these experimental data it is concluded, that in relation to benzene the electrons of the CH-bonds in azulene are displaced towards the C-atom at positions with high and towards the H-atom at positions with low π-electron density. Such a polarisation of the CH-bonds in azulene is confirmed, although only qualitatively, by the ionicities of the CH-bonds calculated by the CNDO/2-method and is also in accordance with other experimental observations such as bond lengths and angles, C13H-coupling constants, and the frequencies of the CH-stretching vibrations. It is demonstrated that experiment and calculation fail to correlate quantitatively due to in-adequacies inherent in the CNDO/2-method.