This thesis is to find the political relationship between the King's material relatives and eunuches during Myongjong of Chosen dynasty. Also, I would search the real causes why, at that time, the eunuches' political power was more powerful than any other time. First of all, Park's political power was originated from the relationship with the Queen Mother Munjong who had powerful political powers. And so, he could obtained many political power and status in the kingdom Specially, King Myongjong also wanted and stimulated the eunuches powers to obtain his own king power, as well as interested and liked them personally. On the while, the King's material relatives also built their powers with relation to the Queen Mother Munjong. Therefore, there are the very power struggles between the King and his the Queen Mother Muniong. The former depended on Yee Yang and his adviser and a eunuch, jeung Beun to obtain the important infonnations at Court and the latter did Yun Weun-Haeng and his intimate eunuch Park Han-long, as well as the court girls. Under this struggle at Court, Park Han-long could obtain and manipulate a political power and status utilizing the intimacy from the King and Queen Mother Munjong. Finally, I insist that the eunuch's powerful dominance at Court be derived from and related with so-called the stronger political power emergence of the King's material relatives. The King needed the eunuches to build his own power, on the while, the King's mother also did them not only to keep her political powers but also to obtain informations about the King's activities.