The research on the relationship between electricity and economy of North China can make a contribution to the development of electric power industry policy. Based on the history data of electricity demand and economic growth from 1986 to 2010 in North China, the grey-relational theory is applied to determine the keyfactors influencing electricity demand. On this basis, the co-integration model and error correction model are employed to establish the relationship model between electricity demand and economic growth of North China. From the perspective of long-term equilibrium, when GDP increases 1%, total electricity consumption increases 0.8270%; when industrial added value of a share of GDP increases1%, total electricity consumption increases1.3011%; when electric power efficiency increases 1%, total electricity consumption increases by 4.5965%; when urbanization rate increases 1%, total electricity consumption increases3.0079%. Therefore, theelectric power efficiency is the main factor to promote the increase of electricity demand.