Abstract: The blue luminescence materials of xSrO·yAl₂O₃:Eu²⁺,Dy³⁺+m%（molar fraction）（H₃BO₃）（m=15,20,23,25,30,35）were synthesized by the conventional solid state reaction method. The X-ray diffraction （XRD） showed that the phosphors are compounds of SrAl₂O₄, Sr₂Al₆O₁₁ and Sr₄Al₁₄O₂₅ with m=15～20, Sr₂Al₆O₁₁ is the dominant host phases with m=23, Sr₄Al₁₄O₂₅ is t he dominant host phases with m = 25～35. The emission spectra and afterglow curves were investigated by spectrofluorometer and photometer. The results reveal that with the increase of amount of H₃BO₃, the emission peak is shifted to the shorter wavelength side, and then to the longer wavelength side; and the afterglow time increase all the times. The optimum amount of H₃BO₃ to synthesize the blue strontium aluminate phosphors is obtained,and then this paper explained the function of boric acid in the synthesis of the material.