Prolonged inspection of a stimulus in a 3-D space produces an aftereffect in the depth dimension. This paper has two aims: (1) to review the previous studies on the depth aftereffects focusing on the level at which adaptation occurs, and (2) to propose a new model of the depth aftereffects. Conventionally, the depth aftereffects have been explained by adaptation of the lower level mechanisms specialized to each depth cue (e.g. ,binocular disparity or monocular depth cue) . However, recent studies suggest that the depth aftereffects are due to adaptation of the higher level mechanisms sensitive to 3-D shape rather than that of the lower level mechanisms. Author proposes a new model integrating both the conventional- and the recent theories.