We study theoretically the space and time correlation of the ion and ions near the surface, and the contribution of the time correlation due to the surface plasmon excitation to the ion trajectory. We present an expression for the effective potential between two ions at the surface, and propose a new type of the surface-alignment effect. The energy loss due to the surface collective mode (surface plasmon, surface exciton, etc.) is obtained as a function of the distance from the surface plane, from which we calculate the energy loss spectrum by computer simulation. © 1982.