(1-x)SrTiO(3-)xCa(0.4)Sm(0.4)TiO(3) (0.6 <= x <= 0.9) ceramics are prepared through the conventional solid-state route. Powders are calcined at 1200 degrees C and sintered at 1400-1500 degrees C. High density, CaTiO3-like perovskite structures are obtained in the range 0.6 <= x <= 0.9. The phase purity, microstructures and microwave dielectric properties are investigated. With an increase of Ca0.4Sm0.4TiO3 content, the dielectric constant (epsilon(r)) decreases, which is dependent on the difference of ionic polarizability between Ca0.4Sm0.4TiO3 and SrTiO3. The product of dielectric Q value and resonant frequency (Q.f) increases up to x = 0.8, and then decreases due to the abnormal grain growth. The variation of temperature coefficient of resonant frequency (tau(f)) with B-site bond valence and tolerance factor (t) is discussed by using the theory of bond valence and the changes of tolerance factor in perovskite structure. The (1-x)SrTiO3-xCa(0.4)Sm(0.4)TiO(3) (0.6 <= x <= 0.9) ceramics show the dielectric properties of epsilon(r) similar to 101.4-142.7, Q.f similar to 1999.5-5986.3 GHz (at 2.8-4 GHz) and tau(f) similar to 359.8-199.6 ppm/degrees C at different sintering temperatures of 1400 -1500 degrees C for 4 h. (C) 2014 Elsevier B.V. All rights reserved.