In this paper, we propose a spatio-temporal lifelog, that enables us intuitively to understand both the spatial and temporal aspects of a situation. We have designed a new wearable compound omnidirectional sensor comprising a hyperboloidal mirror and multiple paraboloidal mirrors. Using this sensor, visual information is recorded in all directions around the user. Objects are classified as foreground or background according to their distance. The stored log can be viewed using a browser that supports two different views, a spatial view and temporal view, which allow an effective visualization of the situation based on the classification. The user can switch between views depending on the purpose.