This paper investigates driverpsilas behavior of checking a traffic situation by analyzing driverpsilas eye movement when the driver is cognitively distracted during preparation of changing lanes. We made an experiment with a motion-based driving simulator under conditions of several types of secondary tasks. Collected data resulted in lower detection rates of intent of changing lanes, less checking behaviors and longer time length of checking behavior. These facts clarified that there are discrepancies between secondary tasks and no secondary one. It showed an influence of cognitively distracting activity on driverpsilas behavior.