It is the tendency to adopt novel soft magnetic materials in planar magnetic components to have much more attractive features. In this paper, the nanocrystal magnetic strip is used to consist of magnetic core of planar inductor. A novel network model for dynamic stray capacitances of planar inductor with matrix structure is presented. The magnetic core is taken into account to be one part of the equivalent circuit of planar inductor in high frequency, and its electric potential is considered to be suspended. To analyze the dynamic stray capacitance accurately, the 3D FEM model is adopted, and the parameters for dynamic stray capacitance of inductor windings are obtained. By equivalent circuit simulation of planar inductor, the impedance feature of planar inductor is obtained. The test results by impedance analyzer verify the dynamic capacitance network model.