Trivalent dysprosium (Dy3+)-doped sodium-aluminum-phosphate (NAP) glasses were prepared and characterized by their optical absorption, excitation, emission spectra, and decay time measurements. Judd-Ofelt intensity parameters were derived from the absorption spectrum and used to calculate the radiative lifetime and stimulated emission cross section of the F-4(9/2) -> H-6(13/2) and F-4(9/2) -> H-6(15/2) transitions. The luminescence intensity ratio of F-4(9/2) -> H-6(13/2) to F-4(9/2) -> H-6(15/2) transitions of Dy3+ in NAP glasses gives the feasibility of extracting white light. The lifetime and quantum efficiency of F-4(9/2) level is found to be higher than other reported glasses. With increase in Dy3+ ion concentration, the decay from F-4(9/2) level is found to be faster with decrease in lifetime due to cross relaxation between Dy3+ ions.