Abstract.: The experiment was conducted to study the effects of concentration, temperature and solvent on the luminescence decay curves obtained in laser-induced fluorescence (LIF) experiment from fluorescent orange dye. Sample solutions of fluorescence dye were prepared by mixing with ethanol solvents at different concentration. The sample was illuminated with a radiation of 470 nm using a blue laser excitation source. Luminescence spectra were recorded using a compact fiber coupled CCD spectrometer and the results were analyzed.The results showed that both concentration and temperature affected the luminescence decay of orange dye in the same way. The luminescence decay was decreased when the concentration and temperature were increased.The appearance of peak positions was slighly shifted to higher wavelength (lower photon energy) when concentration were varied. Then the results of concentration effect were analyzed using peak fit, the appearance of peak positions was slightly shifted from 601.51 to 604.12, 607.64, and 618.44 nm at the concentration of 50, 60, 70 and 80 % by volume, respectively.