As the growing criterion of electromagnetic wave (EMW)absorption materials, micro/nano-scale magnetic materials are drawing more and more attention for their unique features compared to bulky absorbers. Generally, the complex permeability of micro/nano-scale magnetic absorbers varies in a relatively narrow range, whatever for the storage of magnetic energy or the dissipation of magnetic energy. If so, how the small variation of permeability affects the ultimate performances is still unclear. Here, a strategy of electromagnetic parameters regulation for the magnetic materials is applied to understand the loss contribution in micro/nano- scale magnetic absorbers. After analyzing the evolution of electromagnetic maps of ten ferrosoferric oxide samples, it can be found that the dissipation contribution of permeability for magnetic materials is weaker than that of permittivity, in spite of its significant role in determining the impedance matching characteristics. In summary, this work systematically explores the loss contribution in micro/nano-magnetic absorbers for the first time, which is of great importance in designing and optimizing the microwave absorption properties of magnetic absorbers.