A bluish-green color long-lasting phosphorescent phosphor of N contained Ba2SiO4:Eu2+ for X-ray and cathode ray tubes are prepared with the chemical component formula Ba2SiO4:0.01Eu2+ − xSi3N4 − 2BaCO3 (x = 0.1 to 1.0) by the conventional high-temperature solid-state method. The phosphorescence and fluorescence properties as a function of Si3N4 content and temperature are investigated. The emission spectra show a single broad band peaking at 505 nm, which are ascribed to the 4f65d1 → 4f7 transition of Eu2+. Thermoluminescence (TL) glow-curves show that Ba2SiO4:0.01Eu2+ without N holds a high-temperature peak at 417 K. With increasing the content of Si3N4, the phosphorescence grows super-linearly and some new TL peaks appear at low temperatures of about 400, 355, 365, and 335 K. These peaks are ascribed to the formation of new traps related to N substitution for O.