Novel high quality factor microwave dielectric ceramics (1-x)ZrTiO4-x(Mg1/3Nb2/3)TiO4 (0.325x0.4) and (ZrTi)(1-y)(Mg1/3Nb2/3)(y)O-4 (0.2y0.5) with the addition of 0.5wt% MnCO3 in the (Mg1/3Nb2/3)O-2-ZrO2-TiO2 ternary system were prepared, using solid-state reaction method. The relationship between the structure and microwave dielectric properties of the ceramics was studied. The XRD patterns of the sintered samples reveal the main phase belonged to -PbO2-type structure. Raman spectroscopy and infrared reflectivity (IR) spectra were employed to evaluate phonon modes of ceramics. The 0.65ZrTiO(4)-0.35(Mg1/3Nb2/3)TiO4-0.5wt% MnCO3 ceramic can be well densified at 1240 degrees C for 2hours and exhibits good microwave dielectric properties with a relative permittivity (epsilon(r)) of 42.5, a quality factor (Qxf) value of 43520GHz (at 5.9Ghz) and temperature coefficient of resonant frequency ((f)) value of -5ppm/degrees C. Furthermore, the (ZrTi)(0.7)(Mg1/3Nb2/3)(0.3)O-4-0.5wt% MnCO3 ceramic sintered at 1260 degrees C for 2hours possesses a epsilon(r) of 31.8, a Qxf value of 35640GHz (at 6.3GHz) and a near zero (f) value of -5.9ppm/degrees C. The results demonstrated that the (Mg1/3Nb2/3)O-2-ZrO2-TiO2 ternary system with excellent properties was a promising material for microwave electronic device applications.