The relations between the scattering matrix and relative Bloch permeability of periodic symmetric magnetic resonance metamaterial are investigated in detail by means of network theory and Floquet's theorem, and we retrieve the Bloch constitutive parameters for four split ring resonators using the relations. Full wave simulations in conjunction with numerical retrieval algorithms show that when we load the interdigital capacitance at the gap of split ring resonator, the magnetic resonance frequency drastically lowers. Our work provides not only theoretical foundation for the Bloch permeability parameter retrieval from periodic metamaterials, but also a novel design way of miniaturizing magnetic resonance metamaterial configurations.