Abstract. In this work the C=O vibrational band of ethylacetate was studied using Raman scattering spectra and ab-initio calculations. The obtained experiment and ab-initio calculations show that the band corresponding to the C=O stretching vibration of ethylacetate is complex and consists of several bands. ab-initio calculations were performed in the B3LYP 6-311++G (d,p) basis set, and electro-optical parameters, molecular electrostatic potential (MEP) surface, charge distribution and bond lengths of monomers and dimers of ethylacetate were determined.