Blue-emitting Ca2B5O9Cl:Eu2+ phosphors have been synthesized by solid state reaction. The photoluminescence excitation (PLE) spectra show broad-band absorptions and can match the emission of near ultraviolet (n-UV) chip well. At lower Eu2+ concentration, the emission band can be resolved into two bands, which is assigned to the 5d -> 4f transition of Eu2+ ions substituting two different Ca2+ sites. At higher Eu2+ concentration, the energy transfer from Eu(1) to Eu(2) happens and is very efficient. At higher temperature the phosphor exhibits a lower temperature quenching effect. The fluorescence lifetimes are short enough for application in solid-state lighting. The electroluminescence spectrum indicates that the emission of chip can almost be absorbed by phosphor and down-converted into an intensive blue light. The chromaticity coordinates of fabricated light-emitting-diodes (LEDs) is very close to that of BaMgAl10O17:Eu2+ (BAM). Ca2B5O9Cl:Eu2+ is a good blue component phosphor for n-UV excited solid-state lighting.