In the present study, nano-size powders of ternary ferrites, Ni 0.5 Zn 0.5 Fe 2 O 4 , as the potential catalysts of CO 2 decomposition, were prepared by the wet processing of hydrothermal synthesis and coprecipitation method, and the catalyzing effects of impregnation of the noble metals, Pt and Pd, onto Ni 0.5 Zn 0.5 Fe 2 O 4 for the CO 2 decomposition were investigated. XRD results of the synthesized ferrites showed a typical spinel structure of ferrite and the particle size was very small as about 6~10 nm. BET surface area of the ternary ferrites was not affected by the impregnation of Pt and Pd. The reactivity of the CO 2 decomposition to carbon was improved by the impregnation of the noble metals of Pd and Pt. The effect of Pd-impregnation on the CO 2 decomposition rate was higher than Pt-impregnation.