Abstract: In this paper the polarized Iumminesence spectra are reported for TbP_5O_(14). These spectra were obtained at 77 k. The polarization of each line was measured by the ratio (I_(//)-I_⊥)/(I_(//)+I_⊥), where I_(11)(I_⊥) is the intensity of this line when polarized direction and the analyser is parallel (perpendicular). In according to the polarized ratio the stark levels of ~5D_4 and ~7F_J can be assigned. First, on the basis of the polarized character of spectra of ~5D_4—~7D_0(A_1) transition the level's name of ~5D_4 stark levels are assigned. Second, on the basis of the polarized character of ~5D_4—~7F_J transition the level's name of ~7F_J stark levels are assigned. The polarized character of the line of ~5D_4—A_2, ~5D_4—B_1, ~5D_4—B_2 and ~5D_4—E transition aren't regular and their assignment is complicated.