the purpose of grounding are to protect personal safety, to ensure the normal working of machines and to avoid being destroyed. In power system, various kinds of equipments and lighting protection, grounding is used widely. At the moment when cities and towns developing quickly and population get more centralized and building grow taller and taller, many powerful valuable equipments have been put in greed use in offices, families and so on. It is vital to choose reasonable grounding and wiring to a building. The essay analyses the methods to select building grounding, wiring , grounding object and grounding parameter.