The microwave dielectric properties of the (1-x)CaTiO3-xCa(Zn1/3Nb2/3)O-3 ceramic system have been investigated. The ceramic samples sintered at 1300 degrees-1450 degrees C for 4 h in air exhibit orthorhombic pervoskite and form a complete solid solution for different x value. When the x value increased from 0.2 to 0.8, the permittivity epsilon(r) decreased from 115 to 42, the unloaded quality factor Q x f increased from 5030 to 13 030 GHz, and the temperature coefficient tau(f) decreased from 336 to -28 ppm/degrees C. When x = 0.7, the best combination of dielectric properties, a near zero temperature coefficient of resonant frequency of tau(f)similar to -6 ppm/degrees C, Q x f similar to 10860 G Hz and epsilon(r) similar to 51 is obtained.