Pure　perovskite　phase　Ba0.5Sr0.5TiO3　powders　were　synthesized　by　facile　co-precipitation　using　inexpensive　TiOSO4　as　the　raw　material.　The　post-calcining　treatment　was　at　the　low　temperature　of　950　degrees　C,　which　was　about　200　degrees　C　lower　than　that　of　the　conventional　solid-state　method.　The　effects　of　two　types　of　precipitation　agents　on　the　properties　of　Ba0.5Sr0.5TiO3　powders　were　investigated,　and　cubic　Ba0.5Sr0.5TiO3　particles　were　obtained　at　the　optimal　conditions.　Afterwards,　the　obtained　Ba0.5Sr0.5TiO3　ceramics　were　ground　into　fine　ceramic　powders,　and　modified　with　oleic　acid　to　improve　the　compatibility　with　the　polystyrene　(PS)　matrix.　The　modified　ceramic　powders　were　dispersed　in　PS　via　solution　co-blending　to　obtain　Ba0.5Sr0.5TiO3/PS　composites.　The　structure　and　morphology　of　the　Ba0.5Sr0.5TiO3/PS　composites　were　characterized　through　X-ray　diffraction　(XRD),　and　scanning　electron　microscopy　(SEM).　The　SEM　images　showed　that　the　modified　ceramic　powders　had　good　dispersion　in　the　PS　resin.　Moreover,　the　dielectric　and　thermal　properties　of　the　Ba0.5Sr0.5TiO3/PS　composites　were　investigated,　and　the　results　showed　that　the　modified　ceramic　powders　could　enhance　the　dielectric　constants　and　thermal　stability　of　ceramic-polymer　composites.　(C)　2014　Elsevier　B.V.　All　rights　reserved.