In this communication, we report on the synthesis and characterization of a series of compounds with the general composition Ce 1 - x Sr x O 2 - x (0.0=<x=<1.0), to establish a detailed phase relation in the CeO 2 -SrO system. The X-ray diffraction (XRD) pattern of the each product was refined to determine the solid solubility and the homogeneity range. The solid solubility limit of SrO in CeO 2 lattice, under the slow cooled conditions, is represented as Ce 0 . 9 1 Sr 0 . 0 9 O 1 . 9 1 (i.e. 9mol% of SrO). A careful delineation of the phase boundary revealed that the stoichiometric SrCeO 3 , in fact, contains a little amount of CeO 2 also. The mono-phasic compound could be obtained at the nominal composition Sr 0 . 5 5 Ce 0 . 4 5 O 1 . 4 5 . The nominal composition Sr 2 CeO 4 , under the heat treatment used in the present investigation, was a bi-phasic mixture of SrCeO 3 and SrO. No new ordered phases were obtained in this system.