The microwave dielectric ceramics 0.65CaTiO3 0.35LaAlO3 (CTLA) was prepared by solid state reaction technique. The crystal structure, sintering properties and microwave dielectric properties of the CTLA ceramics were investigated. The results showed that the CTLA ceramics only had the main phase of Ca0.65La0.35Al0.35Ti0.65O3 without a second phase. The CTLA ceramics sintered between 1 380~1 450 ℃ exhibited excellent microwave dielectric properties:εr=44.5，τf≈0,Q×f≈43 948 GHz.The additives of 10% Nb2O5 increased densification sintering temperature to 1 300 ℃ but microwave properties was variant. εr=38，τf=-2.8×10-6/°C and Q×f=13 260 GHz.