Lead-tin-fluorophosphate (PTFP) glasses with different concentrations of organic dye stilbene 3 were prepared by low temperature melting. The molecular aggregation and spectrum properties of stilbene 3 doped lead-tin-fluorophosphate glass were studied by means of emission spectra, excitation spectra and absorption spectra measurements. The results show that stilbene 3 dimers coexist with its monomers in inorganic glass. Compared with the excitation peak of stilbene 3 monomer, the excitation peak of stilbene 3 dimer is in the range of shorter wave band. As the concentration of stilbene 3 in the doped PTFP glass increased, the emission peak was red shifted and the concentration quenching of stilbene 3 was observed in the emission spectra. Compared stilbene 3 in PTFP glass with that in ethanol, a remarkable red shift of the absorption and emission spectra in the glass was found. The phenomenon is explained by the bond effect between stilbene 3 and matrix glass by hydrophilic interaction. And a much higher fluorescence intensity of stilbene 3 in the inorganic glass than that in ethonal is attributed to the "cage" effect.