A method of preparing a halophosphate phosphor represented by Formula 1, the method comprising: mixing a metallic precursor compound, which comprises strontium pyrophosphate, strontium chloride and strontium carbonate, and an activator precursor compound to form a mixture; sintering the mixture under an oxygen or air atmosphere to form a sintered mixture; milling the sintered mixture to form a milled product, and sintering the milled product under a reducing atmosphere: (Sr5-(x+y)AxM′y)(PO4)3Cl.(M2O3)z  Formula 1 wherein A is barium or calcium, M′ is an activator and comprises at least one cation selected from the group consisting of Eu2+, Mn2+, Sb2+, Ce3+, Pr3+, Nd3+, Sm3+, Tb3+, Dy3+, Ho3+, Er3+, Yb3+ and Bi3+, M is aluminum, yttrium or lanthanum, 0≦x≦4.8, 0