This paper reports that the long persistence phosphor pf MgF

2

:Mn

2+

is synthesized successfully at 900C. Authors suggest the use of magnesium carbonate basic and ammouium fluoride as starting materials

and the relationship expressed by the reaction equation:Mg(OH)

2

·4MgCO

3

·6H

2

O+10NH

4

F-MgF

2

+12H

2

O+4CO

2

+10NH

3

is studied as a function of preparation temperature. The optimum conditions for preparating the samples have been examined. It shows that the concentration of Mn

2+

ion is about 0.5mole%.Emission spectra of MgF

2

:Mn

2+

phosphor are measured from 400nm to 700 nm and that of a typical sample is shown in Fig.2. The emission color of the phosphor is orange-red with chromaticity x=0.599

y=0.438. The emission peaks for these samples occur at 590nm. The luminance varies with the voltage or current density (Fig.3 and Fig.4). The cathode luminescence characteristics of the samples are studied. Luminescence brightness and persistence of MgF

2

:Mn

2+

phosphors are superior to P33 phosphors.