A new solid sample inlet interface was mounted on a homemade time-of-flight mass spectrometer, and the ion source structure was rebuild. Several Rhodamine dyes was analyzed by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. A KrF excimer laser output at 248nm is used to induce the desorption ionization process. The matrix material 2,5-dihydroxybenzoic is used in all experiments. Characteristic fragmentation mass spectra of these species are detected. The influence of laser power and the optimal matrix/analyte molar ratio on repeatability and resolution of the mass spectra was also studied. It was found that one can use a single wavelength laser to carry out the detection of numerous species if the analyte and the matrix can be dissolved in the same solvent.