The purpose of this study was to examine which facial part, the upper or lower half of the face, is more important to the perception of motion facial expressions. Participants were presented with motion stimuli of facial expressions of approximately 2-second duration. Different facial expressions of brief duration (either 200 msec or 330 msec) were inserted in the middle of those motion stimuli. Such momentary changes in facial expressions were confined to either the upper or lower half of the face. Participants were asked to categorize the inserted facial expressions into anger, happiness, neutral or sadness, or to rate apparent liking expressed in the entire motion stimuli. The results indicate that the important feature of anger (and, to a much lesser extent, of sadness) is expressed in the upper half of the face whereas that of happiness is contained in the lower half of the face.