The complex electrical properties of natural pyroxenite were measured over a frequency range from 0.01 to 106 Hz, at 3.0GPa and 1266-1504K, using the solid buffers (Mo-MoO2) to control the oxygen fugacity. Thefrequency dependence of electrical properties for the natural pyroxenite is investigated. Two distinct conduction mechanisms of the natural pyroxenite are observed: grain interior and grain boundary conduction. Grain interior transport controls the response above 100 Hz, whereas grain boundary transport dominates between ～ 100 and 0.01 Hz. Electrical response of natural pyroxenite is modelled with an equivalent circuit in which parallel RC circuit elements representing grain interior and grain boundary responses act in series. The grain boundaries do not enhance the total conductivity of natural pryoxenite. The total electrical conductivity of natural pyroxenite is lower than either grain interior or grain boundary conductivity alone.