Polycrystalline Ba 2 TiP 2 O 9 phosphor was synthesized and its crystalline state was checked by X-ray diffraction. Its luminescence properties were investigated under UV excitation and X-ray excitation. The phosphor is efficiently excited by UV light and X-ray irradiation and presents a bright blue green luminescence band with a peak centered at about 490nm. The luminescence quantum efficiency (QE) and the X-ray excited emission spectra of Ba 2 TiP 2 O 9 phosphor were compared with those of a highly efficient scintillation material, Bi 4 Ge 3 O 12 . Ba 2 TiP 2 O 9 phosphor shows higher QEs under UV excitation and comparable QE under X-ray excitation. It is suggested that the luminescence of Ba 2 TiP 2 O 9 arises from isolated centers of octahedral TiO 6 .