Abstract: Uranyl luminescence in phosphoric acid system is studied in this communication. Excited uranyls by nitrogen laser appear single or bi-exponential luminescence decays in phosphoric acid system, when uranyl or phosphoric acid concentrations are lower, single exponential luminescence decays appear, whereas with higher concentration of uranyl or phosphoric acid, biexponential decays are observed. Time-resolved spectra are measured. The reasons of the phenomena might be resulted from the luminescences of the long-lived *UO2H2PO4(H3PO4)2+and the short-lived * UO2 (H3PO4) 32+.