Microwave wide-spread results in electromagnetic interference, environmental pollution, and hazards for health, thus microwave absorber is immediately needed. Mn4+doped barium natural ferrites were synthesized using the modified solid-state reaction method, which is a combination of the sol-gel method and the solid-state reaction. Commercial Ba(NO3)2, MnO2 and natural Fe3O4 were used as raw materials. Structural, magnetic properties and microwave absorption of the barium ferrites were characterized using XRD, VSM, and VNA, respectively. The results reveal that phase of BaFe2.37Mn9.63O19 dominates the diffraction peaks with the average size of crystallite 23.74 nm after adding Mn4+ ions in the barium ferrites. Ms value of the barium ferrite decreases with increasing concentrations of Mn4+ due to the surface effect of the nanoparticle. The MBF3 exhibited excellent performance that absorbs all given microwave frequencies with RL below -10 dB and bandwidth of 4 GHz compared to the other samples.