This paper deals with silicate long afterglow phosphors. It is reported in the first time that the afterglow time of the silicate phosphors can be last more than ten hours. Series of silicate long afterglow phosphors doped with Eu were made in M-M′O-SiO

2

(

M

=Ca

Sr

Ba;

M′

=Mg

Zn

Cd) system. It is found that disilicate of akermanite structure and silicate of okenite structure doped with Eu

2+

Ln

have the best afterglow properties. The excitation and emission spectra

afterglow characteristics of the above phosphors were measured and investigated. The luminescence comes from typical 5d→4f transfer of Eu

2+

. Emission color responds to M and structure

it changes continuously from blue to yellow. It is shown in decay curve that its afterglow property is better than the traditional (Ca

Sr) S:Bi blue long afterglow ph osphors. The best afterglow property comes from disilicate doped with Eu

whose afterglow time is more than ten times of (Ca

Sr)S:Bi

after illuminating stopped 60min. Thermoluminescence spectra identified the existence of long afterglow luminescence. It is known by the measurement of X-ray diffraction patterns that the luminescent material is akermanite crystal. It is shown by the result of anti-water experiment that the anti-water property of CaSr silicate phosphor doped with Eu

2+

is obviously better than that of aluminates system long afterg low phosphors.