An equivalent network analysis for an arrangement that combines a microstrip line and coaxial conductor for the purpose of measuring permeability is discussed in this paper. The measurement circuit used consists of a coaxial conductor with a sample housed inside and a short microstrip line connected to both sides. The coaxial conductor is composed of an electrically grounded coaxial metal pipe with open ends and a center conductor. Equivalent networks for this arrangement are investigated to determine the complex permeability from the impedance of the measurement circuit. We have employed a π network composed of a resistor and an inductor connected in series, and shunt capacitors as the equivalent circuit for the measurement portion. It has been found that the measurement error ratio of less than a few percent can be obtained for most frequency ranges of 10MHz to 500MHz.