 The mechanism of negative permittivity slash permeability in random metamaterials is still unclear due to their random characteristic and precise control of microstructure and electromagnetic properties. Silver was introduced into porous SiO2 microsphere matrix by a self-assemble and template method to construct the random metamaterials, resulting in precise regulation of electrical percolation with increasing silver content. Negative permittivity came from the plasma-like behavior of silver network, while negative permeability was explained by the magnetic response of eddy current in silver micro-network. The calculation results showed a linear relation between omega 0.5 and negative permeability, demonstrating potentials for electromagnetic attenuation and shielding with enhanced absorption and intelligent frequency selection even in thin thickness. This work provides a clear physical image for the theoretical explanation of negative permittivity and negative permeability in random metamaterials and a novel strategy to precisely control their microstructure. This article was authored by Paitao Xia, Zidong Zhang, Zhongyang Wang, and others. We are article.tv, links in the description below.