Zn-doped Li2Mg1-xZnxTi3O8 ceramics with spinel structure were synthesized by the conventional solidstate reaction method. The effects of Zn doping on the phase structure, microstructure and microwave dielectric properties of Li2MgTi3O8 ceramics were discussed. When the amount of Zn doping is 0.06, Li2Mg0.94Zn0.06Ti3O8 ceramic sintered at 1 075 ℃ for 4 h showed the best microstructure and microwave dielectric properties with a moderate dielectric constant of 26.58, a higher Q×f of 44 800 GHz, and a temperature coefficient of resonant frequency of +1.9 μ℃-1. The ceramic materials have good microwave dielectric properties, which can be used in the development of microwave dielectric substrate materials as inorganic filler materials.