Abstract: Through the comparative study on the solid solutions of the Rhodmine B in PMMA, theyare found to be effective to produce fluorescence. Spectrum analysis by fluorescence spectrophotometerreveals that the materials appear to produce anti-stokes fluorescence peak with excitation sources atwavelengths longer than those corresponding to the peak of the luminescent bend. This means fluores-cence photons have redundant energy than pumping photons. That is to say that the Rhodamine B-doped PMMAs are potential material for laser cooling. One of the materials we proposed is solid solu-tion of Rhodamine B in PMMA. It is excited at 630nm and produced fluorescence peak about 595nm, and has energy difference of 0.11 eV.