In-situ experimental measurements of the electrical conductivities of minerals and rocks under high temperature and high pressure are the important approaches to explore the chemical composition and evolution process of materials in Earth’s interior, as well as to interpret the inversion results of the magnetotelluric and geomagnetic deep sounding data. In this paper, above all, some crucial influence factors on the electrical properties of mineral and rock such as temperature, pressure, water content, iron content, oxygen fugacity and melting are described in detail. Secondly, four typical kinds of electrical conduction mechanisms of minerals and rocks are demonstrated (e.g. ion, proton, small polaron and large polaron) at high temperature and high pressure. Finally, conduction mechanisms and geophysical applications are discussed based on the recent research results of electrical conductivities for feldspar, quartz and pyroxene on the major rockbearing minerals in the crust, and the present problems and future research work are discussed.