A novel reddish orange light emitting phosphor, CaSnO3 :Sm3+, is prepared via a two-step approach including the room temperature synthesis of CaSn(OH)(6) precursor and then convert it into CaSnO3 by calcination and its optical properties are systematically investigated. X-ray diffraction, photoluminescence, long persistent phosphorescence and thermoluminescence spectra are used to characterize the synthesized phosphor. This phosphor is found to be well-crystallized by calcination at 750 degrees C for 3 h . Photoluminescence measurement indicates that Sm3+-doped CaSnO3 shows an overall reddish orange emission with a CIE values of x = 0.57, y = 0.37. After irradiation under the 254-nm UV light, the (4)G(5/2) to H-6(J) (J = 5/2,7/2,9/2,11/2) afterglow emissions Of Sm3+ are obviously observed. Furthermore, the thermoluminescence and the possible mechanism for the long persistent phosphorescence (LPP) of the CaSnO3:Sm3+ phosphor is also discussed in this paper. (c) 2006 Elsevier B.V. All rights reserved.