Magnetic gear has various advantages related to its capability as contactless moving gear with no lubrication and its overload protection ability. The magnetic gears are commonly used as a transmission that demands high torque characteristics. This paper aims to perceive the effects of the design parameters of Coaxial Magnetic Gear (CMG) on the transmitted torque and the magnetostatic field. Furthermore, the magnetic field and torque characteristics of CMG were inspected by ANSYS/Maxwell commercial software. The proposed CMG was developed using the Taguchi method. This method allows investigating performance under various factors. This paper used four levels in five factors that compose the radial length of the outer and inner iron part, the radial length of outer permanent magnet and inner permanent magnet, and the radial length of pole pieces. ANOVA test showed that the five factors contribute to the transmitted torque. The outer iron part acquires 86.49% contribution, which is the highest contribution, and the outer permanent magnet contributes 1.93%. The percentage of the pole pieces and inner permanent magnet contribution is 2.99% and 6.94%, respectively. Another factor, the inner iron part, was pooled because it did not significantly contribute to the torque. Using the Taguchi method, the transmitted torque prediction was 1861.33 N.m., while the simulation obtained 1853.96 N.m. Finally, the research result can be a consideration in designing transmitted torque demand.