A naturally luminescent bacterium, Photobacterium phosphoreum was stored in 2.5% NaCl solution at 2$0^{circ}C$, 4$^{circ}C$, -2$0^{circ}C$ and -7$0^{circ}C$ for 30 days. In vivo luminescence and concentrations of total and culturable cells were determined by luminometer, spectrophotometer and dilution plate counting, respectively. When stored at 4$^{circ}C$ and 2$0^{circ}C$, concentrations of cells were rapidly decreased as a result of cell lysis, leading to adrop in turbidity and cultured counts. The bioluminescence of cells stored at 4$^{circ}C$ was maintained until 12 days while those of cells starved at other temperatures decreased to background level within 3 days. Following incubation of stored cells in fresh liquid medium, activities of viable cells increased throughout storage period excepting cells stored at 2$0^{circ}C$. Changes in bioluminescence intensity following addition of 2.5% NaCl solution markedly showed in cells stored at -2$0^{circ}C$ and -7$0^{circ}C$ and increased to maximum 8 fold.