The xCa0.8Sr0.2TiO3-(1-x)Li0.5La0.5TiO3（CST-LLT）（x=0.4～0.8） microwave dielectric ceramics were prepared by the solid state reaction method. The phase composition, microstructures and microwave dielectric properties of ceramics were investigated. The results indicate that the prepared ceramics has perovskite structures. The dielectric constant εr varied from 154.8 to 275.2 at the sintering temperature of 1 170～1 260 ℃ with the decrease of Li0.5La0.5TiO3 contents. The Q·f value increased first and then reduced gradually over the range of 1 360 GHz to 1 479 GHz, and the temperature coefficient of resonant frequency τf varied from -720.6×10-6/℃ to 470.5×10-6/℃. With x=0.5, CST-LLT ceramics sintered at 1 200 ℃ for 3 h exhibited proper dielectric properties of εr=230, Q·f=1 455 GHz and τf =24.5×10-6/℃.