Recently, barium ferrite nanoparticles have attracted substantial attention because of widespread applications in catalytic degradations, credit cards, storage hardwares, sensors, microwave devices, permanent magnets, high frequencies, photocatalytic catalysts, and etc. In this research, templated BaFe₁₂O₁₉ nanoparticles were prepared through the sol-gel method by use of cotton as a template in the sol step. Finally, templated nanoparticles were blended in the silicone rubber matrix and then prepared nanocomposite molded to investigate of microwave absorption properties at x-band frequency. Templated barium hexaferrite nanoparticles were characterized by Fourier transform infrared (FT-IR), diffuse reflection spectroscopy (DRS), vibrating sample magnetometer (VSM), field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), and microwave absorption characteristics were obtained by vector network analyzer (VNA). Microwave absorption curves showed that Templated BaFe₁₂O₁₉/silicone rubber nanocomposite absorbed 65.80% of microwaves at 9.87 GHz.