In this communication, we report on the bulk and lattice thermal expansion studies on a number of compounds, within the homogeneity range of solid solutions, in a series with the general composition Ce 1 - x Sr x O 2 - x (0.0=<x=<0.10). The XRD pattern of each product was refined to determine the solid solubility of SrO into the lattice of CeO 2 , and the homogeneity range. The composition with maximum solid solubility limit of SrO in CeO 2 lattice, under the slow cooled conditions, was delineated as Ce 0 . 9 1 Sr 0 . 0 9 O 1 . 9 1 (i.e. 9 mol.% of SrO). The bulk thermal expansion measurements from ambient to 1123 K, as investigated by a dilatometer, revealed that the α l (293 to 1123 K) values for the compositions within the homogeneity range increase from 11.58x10 - 6 to 12.13x10 - 6 K - 1 on increasing the Sr 2 + content from 0 mol.% (i.e. CeO 2 ) to 9 mol.%, i.e. the upper solubility limit of SrO into the lattice of CeO 2 . A similar trend was observed in the lattice thermal expansion coefficients α a (293 to 1473 K) as obtained by a high temperature-XRD.