We perceive self-motion by integrating visual, vestibular and somatosensory information. In this research, we manipulated visual information and vestibular/somatosensory information to simulate the translational motion of acceleration and the rotational motion about the horizontal axis (pitch motion). In addition, we introduced a time lag of the visual information from the vestibular/somatosensory information. Subjects responded the magnitude of self-motion. The results showed that the temporal lag between these stimuli weaken the perception of the translational motion and strengthen the perception of the pitch motion.