Abstract: The dependence of magnetic properties on microstructure of Co₂Z was analyzed. Through introducing pre-magnetization in ordinary ferrite fabricating technology, and controlling the growth of prodigious crystalloid, a Co₂Z wide-frequency material was prepared. Experimental results show that the resonance frequency of the Z-type ferrite is over 1.8GHz, cut-off frequency is about 1GHz,the initial permeability μ_i is between 8 and 13 , and the dielectric constant ε is lower than 30.