The microstructure and microwave dielectric properties of dielectric ceramics comprised of ZnNb2(1-x)TixO(6-3x) (x = 0 ~ 1) were investigated systematically using X-ray powder diffraction, SEM and a network analyzer in this study. The results showed that four phases were observed in this system. The dielectric properties at microwave frequencies exhibit a significant dependence on the composition and crystal structure of the ceramics. The dielectric constant ( er) of ZnNb2(1-x)TixO(6-3x)ceramics increases with increasing Ti content and the quality factors (Q ×f) significantly decreased. However, the temperature coefficient of resonant frequency ( t f ) changes from –59.08 ppm/oC at x = 0 to + 25.1 ppm/oC at x = 1, and a zero temperature coefficient of resonant frequency ( t f ) for this ceramics system was obtained at x = 0.84.