Luciferase is a general term for enzymes that produce biofluorescence in nature. Luciferase can catalyze the oxidation of luciferin to oxyluciferin. In the process of luciferin oxidation, biofluorescence is emitted. The biofluorescence released during the oxidation of luciferin can then be measured by a fluorometer. The Luciferase came from the firefly Photinus pyralis （Ppy） catalyzes a two-step reaction that results in the oxidation of D-luciferin accompanied by emission of yellow?green light with a peak at 560 nm. However, wild-luciferase activity is inhibited by sodium chloride, Therefore, the amino acid mutation we performed improved the inhibition of sodium chloride and was eventually named Luciferase Ⅰ.