The magnetic properties of MgCuZn ferrite samples with varied microstructures prepared by conventional solid-state reaction method were studied for the application of the near field communication (NFC) system. The results show that the densely sintered sample with small grains possesses the most satisfactory magnetic properties. Specifically, the Q factor, the real and imaginary part of the permeability of the sample at the frequency of 13.56 MHz are 33.40, 117.22 and 3.51 respectively. Furthermore, the effects of microstructure on the permeability spectra of the ferrite samples are investigated systematically via the numerical fitting method. It is observed that both grain size and pore greatly impact on the static susceptibility of domain wall motion K_dw, and static spin susceptibility K_spin, and the damping factor of the domain wall motion β is greatly affected by the closed pores. The theoretical analysis indicates that lowering β is more significant than adjusting K_dw or K_spin for the purpose of high real part of permeability and Q factor. Based on theoretical expectation, the better magnetic properties can be obtained by the further improvement on the microstructure of materials.