the ultraviolet absorption spectra and fluorescence spectra for acetic acid solution under the wavelength of 254nm (Δλ1/2(4nm) UV light excitation are measured by a grating spectrometer. And their emitting mechanism and spectral characteristic are investigated. The experimental results and theoretic analyzing about it are presented in this paper. It shows that the acetic acid solution emitting fluorescence quantum yield efficiency under 254nm excitation may reach above 50%, the fluorescence result from the -C=O- fluorophores in acetic acid molecule, the fluorescence quantum yield of acetic acid solution changes as the concentration alternates. Investigation on the ultraviolet absorption spectra and fluorescence spectra and their characteristics will contribute to study other organic macromolecule fluorescence spectra when acetic acid serves as solute and hydrolysis catalyst.