The four characteristic parameters of the fluorescence spectrum of ethanolwater solution have been studied. Their timedomain and frequencydomain characteristics have been obtained too. The emission and excitation spectra have indicated that there are three luminescent substances with different molecular structures in the ethanol-water solution. The fluorescence peaks center at 290 nm, 305 nm and 330 nm with the corresponding optimal absorptive peaks located at 265 nm, 280 nm and 236 nm, respectively. The variation of the fluorescent intensity with the volume fraction of ethanol also attests to the existence of the three different luminescent substances. The decay process of fluorescent intensity is detected at the center of the emission peaks, and it is fitted by an exponential function and the analyzed data are obtained by deconvolution. The fluorescence lifetimes are 8 ns, 12 ns, and 25 ns, respectively. From the four fluorescence characteristic parameters of ethanolwater solution, it can be concluded that when ethanol and water molecules are gathered together the clusters with new structures are formed which can emit fluorescence photons with different energy. The research contributes to the study of the molecular structure characteristic of ethanolwater cluster.