In the present paper, the authors studied Guoyuan and Yanghe which are the most representative types of Su liquor. The authors got the three-dimensional fluorescence spectra of the liquor and analyzed their unique characteristics. Guyuan has obvious characteristics of the fluorescence in the 280-400 nm excitation wavelength range, including a major peak of fluorescence. Yanghe contains five clear fluorescence peaks in the 200-450 nm range of excitation wavelength. The two series of liquor have clear fluorescent characteristics in the 310-350 nm range of excitation wavelength, The range includes some organic compounds which play a decisive role in taste and flavor of Su liquor. The result of research provides a scientific basis for improving the mixing process of Su liquor and enhancing the quality of liquor.