Reaction mechanism of synthesis of europium-activated strontium fluorobo-rate phosphor has been investigated and the optimum reaction conditions for the formation of this phosphor have been evaluated and determined. Firing of a mixture of SrCO

3

SrF

2

H

3

BO

3

NH

4

F and EuCl

3

at temperature higher than 730℃

SrF

0.1

B

4

O

6.95

:Eu is the main product. As the firing temperature is lower than 730℃

a product of SrB

6

O

10

:Eu with weak emission might be formed. It was found to fire th3 product at 870-900℃ once more

so as to make the phase transformation of SrB

6

O

10

to SrB

4

O

7

comlpete. Firing atmosphere shows certain influence on the luminescence intensity of the product.Firing in the presence of granular active charcoal (i.e.in an atmosphere of CO+CO

2

) would be the most favorable. The optimum activator concentration was determined to be 0.01mole/mole host. As it is higher than 0.015mole/mole host

concentration quenching would occur.By the X-ray diffraction

thermogravimetric as well as chemical analysis of Sr

2+

and Fions the chemical composition of the phosphor was determined and its general formula can be written as(l-x)SrO·xSrF

2

·2B

2

O

3

:yEu 0.02≤x≤0.05 0.005≤y≤0.015.