Barium-Ferrite is one of the common used Ferrite material for it’s high saturation magnetization, coercivity and resistivity, which has a widely application in microwave absorption. Tombarthite-substituted modification of the Barium-Ferrite is the main research direction. M hexa-Barium-Ferrite nano-particles are synthesized by co-precipitation method. The structure and electromagnetic properties of the results is analyzed by X-ray powder diffraction (XRD) and vibrating sample magnetometer (VSM). The vector network analyzer is used to analyze the absorbing properties of the pure and tombarthite-substituted Barium-Ferrite. The results show that the absorbing property of tombarthite-substituted Barium-Ferrite is improved further.