EXtreme ultraviolet spectrosCope for ExosphEric Dynamics (EXCEED) is the earth-orbiting Extreme Ultraviolet (EUV) spectroscope mission which dedicates to the planetary space science. Our mission will carry out the EUV spectroscopic imaging which clarifies the plasma distributions and compositions around the planets and examines the interaction with the solar wind. Orbital altitude should be enough high so that the earth's atmospheric absorption is free. The spectral range of the mission is from 60 to 145 nm and the 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, its instrument and its scientific targets.