Abstract: Z type hexaferrite doped with Zn,Sr₃（Zn_xCo_1-x）₂Fe₂₄O₄1,（x=0～0.8）micro-crystals were synthesized through a citric acid sol-gel method.Their crystal structure,magnetic property,electromagnetic property and microwave absorbing property were studied.The result show that doping with Zn²⁺ appropriately could conduce to the improvement of magnetic properties and absorbing properties.Specific saturation magnetization of Sr₃（Zn_xCo_1-x）2Fe₂4O₄1 had a maximum which is 51.36 A·m²·kg^-1 at x=0.2;Absorption quantity of Sr₃（Zn_xCo_1-x）2Fe₂4O₄1 had a maximum which is 35.12dB at x=0.2 as well;The micro-crystal powders were obtained at 1200℃ and were sintered 2h.