In this paper the synthesis method of Me

2

SiO

4

:Tb

3+

(Me=Ca

Sr

Ba) is reported. The Me

2

SiO

4

:Tb

3+

(Me=Ca

Sr

Ba) were fired at 950℃ for two hours using MeCO

3

H

2

SiO

3

Li

2

O

3

and Tb

2

(C

2

O

4

)

3

with suitable mole ratio

reground

and then retired in air at 1250℃ for three hours. Li

+

ions were added to compensate charges. The crystalline phase was checked by a X-ray powder diffractometer. The excitation and emission spectra were measured by MPF-4 fluorospectrometer.The emission spectra of Me

2

SiO

4

:Tb

3+

(Me=Ca

Sr

Ba) under UV excitation originate from

5

D

3

-

7

F

I

and

5

D

4

-7FJ transitions of Tb

3+

ion. The strongest peak corresponds to the transition of

5

D

4

-

7

F

5

when the concentration of Tb

3+

ion is 0.05-0.3mol. The difference between emission spectra of Me

2

SiO

4

:Tb

3+

(Me=Ca

Sr

Ba) is small. The concentration quenching of the luminescence of Me

2

SiO

4

:Tb

3+

is discussed. It is found that the variation in intensities of

5

D

4

-

7

F

5

and

5

D

3

-

7

F

5

transitions with the terbium concentration is of different trends. The optimum concentration of Tb

3+

ion for Ca

2

SiO

4

:Tb

3+

or Sr

2

SiO

4

:Tb

3+

is about 0.15mol.

and that of Ba

2

SiO

4

:Tb

3+

is about 0.25mol.It is well known that the relationship between the luminescence intensity I and the concentration of activator x can be written as

I/x

=A(1+β

θ/3

)

-1

where θ is a constant related to the interaction between activator ions

A and β are two parameters. We have found that 6 is equal to three for the transition of

5

D

4

-

7

F

5

and 6 for the transition of

5

D

3

-

7

F

5

. This result means that the concentration quenching mechanism for

5

D

4

-

7

F

5

and

5

D

3

-

7

F

5

is different.