Magnetolluric measurements show that the lower continental crust has remarkably high electrical conductivity which is about 10-4~10-2 S/m. Tracing the origin of this phenomenon will have important implications to understand the structure and some typical geological processes in the interior of the Earth. Many mechanisms, among which the most probable candidates are models of hydrous minerals, interconnected saline pore fluids, interconnected grain boundary films of graphite and positive hole pairs, were presented for the explaination. However, none of them is totally reasonable and controversy still exists. Micro-FTIR analysis performed on minerals (plagioclase, clinopyroxene and orthopyroxene) in granulite xenoliths from Nushan demonstrated that all these minerals contained water incorporated in the structure as OH with the content (H2O wt.) up to ~1700×10-6 for plagioclase, ~1600×10-6 for orthopyroxene and ~2400×10-6 for clinopyroxene, respectively. The water (hydrogen) may have dramatic effect on the electrical conductivity of the lower continental crust and thus provides a more possible explanation.