Eu3+-doped Y2O3 red phosphor `was prepared in order to study the relationship between variation of Eu3+ content and an excitation source such as low and high voltage energy and a vacuum ultraviolet (147 nm). The luminescence properties of pigment-coated Y2O3:Eu by various coating methods and different energy sources were also investigated. Excitation under a vacuum ultraviolet (VUV) for the red phosphor with different amounts of Eu3+ activator exhibited similar luminescence property with the case of being excited by electrons accelerated under low voltage conditions. The surface of Y2O3:Eu red phosphor was treated with α-Fe2O3 pigment by two different methods to improve color purity. One was the adsorption utilizing α-Fe2O3 submicron-particles on the phosphor and the other was a precipitation method utilizing Fe(NO3)3-urea or -hexamethylenetetramine (HMTA). The red phosphor treated with an increasing amount of α-Fe2O3 showed decreasing luminescent intensity, but the color purity improved. The luminescent properties of phosphor treated with α-Fe2O3 pigment by the adsorption method exhibited much less dependency on the applied energy source. Surface treatment by the precipitation method, however, resulted in much a faster decrease of luminescent intensity with a lowering of the applied voltage and VUV region because of a more homogeneous coating of α-Fe2O3 pigment on the phosphor.