Abstract: The importance of energy for mankind is pointed out and thenecessity to find new kinds of energy is discussed. Nuclear energy is theonly way to solve this problem, as was forecasted by A. Einsteinone hundred years ago, which has opened a new era ofnuclear energy, where attention was paid to fission and fusion energy.In this paper, the technology to use nuclear energy is presented with detaileddescription of the requirement to use fusion energy, its development and thepresent status, including magnetic confinement and inertial confinement.Now tokamak is the best choice to use fusion energy, so the contribution ofITER is an important step and milestone of the research and development offusion energy. The strategy in energy development in this century in Chinais also disscussed in the last part of this paper.