The solid solution of dielectric ceramic Ca1-xLa2x/3TiO3 system for the composition range of 0.1 less than or equal to x less than or equal to 0.9 is studied. The crystal structure of the system is single perovskite. From the X-ray diffraction patterns, the superstructure reflection lines are detected for the composition x greater than or equal to 0.5. With an increase in the substitution amount of La, the permittivity and the temperature coefficient of resonant frequency (TCF) decrease. A maximum Q x f value of 17600 appears at x = 0.4 since that the extrinsic origin for the dielectric loss degrades the e x f value due to the poor grain growth for the composition x greater than or equal to 0.5. (1-y)Ca1-xLa2x/3TiO3-y(Li,Nd)(1/2)TiO3 compounds are introduced to obtain a good temperature stability of resonant. frequency, With x = 0.4, the composition y = 0.5 shows good temperature stability (tau (f) = +4.5ppm/degreesC) with a high permittivity of 105 and Q x f value of 7000 GHz.