Abstract: The perception of motion-in-depth is still in research. The influence of motion direction on the perception is unclear and not reported. By an experiment paradigm close to human's practical visual experience, this paper presents a detail spatio-temporal analysis of the 128-channels event-related potential (ERP) data under two conditions. The results illustrate that same or similar brain areas are activated in both conditions, but the emphasis brain areas are not same when processing different motion direction, and some significant difference on their temporal course can be observed.