Phase composition and microwave dielectric properties of (1-x)ZnAl2O4-xCo(2)TiO(4) ceramics synthesized by a conventional solid-state reaction were investigated. ZnAl2O4 can form a solid solution with Co2TiO4 for x < 0.3 and x >= 0.7, while subgrains with ZnAl2O4-based and Co2TiO4-based spinel phase composition appear alternately on the same large grains for 0.4 < x < 0.6. The epsilon(r) and tau(f) value of the (1-x)ZnAl2O4-xCo(2)TiO(4) ceramics increase within the range of 8.3-16.9 and -71.3 to -40.8 ppm/degrees C with the increasing of x value, respectively. And the Q x f values with 147 600 GHz at x=0.2, 127 000 GHz at x=0.5, and 148 810 GHz at x=0.8 are all obviously higher than that of the end member ZnAl2O4 (96 800 GHz) and Co2TiO4 (98 060 GHz), which results from structural stability and lower inner stress.