Ca1−xO:Bix=0.5% phosphor powder was successfully synthesized by the sol-gel combustion method. The structure, morphology and luminescent properties of the phosphor were characterized by X-ray diffraction, scanning electron microscopy, photoluminescence and cathodoluminescence (CL) spectroscopy. The results showed that the Ca1−xO:Bix=0.5% consisted of single face-centred cubic crystals and that the phosphor particles were uniformly distributed. When the phosphor was excited by a xenon lamp at 355nm, or a 325nm He–Cd laser, or electron beam, it emitted strongly in the blue near-UV range with a wavelength of 395nm (3P1→1S0 transition of Bi3+). The CL intensity was monitored as a function of the accelerating voltage and also as a function of the beam current. The powder was also subjected to a prolonged electron beam irradiation to study the electron beam induced CL intensity degradation. X-ray photoelectron spectroscopy was used to analyze the Ca1−xO:Bix=0.5% phosphor sample surface before and after degradation.