Abstract: CuO-doped (1-x)Ca0.61Nd0.26TiO3+xNd(Mg1/2Ti1/2)O3 complex microwave dielectric ceramics were produced using conventional solid-state reaction method. The densities, microstructures and microwave dielectric properties after sintering with different x values of composite ceramics were investigated. Results show that when the x value increased, the dielectric constant decreased, but the Q·f increased, and the temperature coefficient of resonant frequency changed from a positive to a negative value, and near zero τf value ceramics could be obtained in the range of x from 0.3 to 0.5; When x was 0.5, an optimal dielectric properties of composite ceramics could be obtained.