EXtreme ultraviolet spectrosCope for ExosphEric Dynamics (EXCEED) will carry out the extreme ultraviolet (EUV) spectroscopic imaging observations from earth orbit. It clarifies the plasma distributions and compositions around the various planets and examines the interactions with the solar wind. Observations should be carried out at high altitude so that the earth's atmospheric absorption is free. Our spectral range is from 60 to 145 nm and the spectral resolution is 0.2 to 0.5 nm (FWHM). The mission is planned to be launched in 2013, beginning of the next period of solar maximum. In this paper, we will introduce the general mission overview, scientific objectives and development of instrument.