The Linguistic Association of Korea Journal, 21(1), 95-115. This paper aims to examine the aspectual functions of the auxiliary verbs ‘nohta’(놓다), ‘dooda(두다)’, ‘beorida’(버리다) ‘naeda’(내다) in Korean. It has been argued that these verbs have the meaning of perfective aspect. But these claims weren`t examined fully in aspectual theory, and arguers depend on intuition in judging perfect. So there is no agreement on the items of perfective auxiliary verbs, and there are many phenomena we cannot accept of these verbs have the meaning of perfect. I observed the concept of perfective aspect overall and presented the conditions of perfective aspect based on the aspectual logic, and discussed whether the auxiliary verbs can be perfective forms. And I concluded that these auxiliary verbs cannot have the meaning of perfective aspect, by showing 14 evidences. For the most, these verbs cannot mark terminal point and complete the action in situation type. The reasons why these verbs have been misunderstood as perfective aspectual forms were explained in this paper. And I argued that they just represent modal meanings.