Executive agency system is known to provide more autonomy to national institutions for better efficiency and enhanced performance level. In South Korea, the National Museum of Modern and Contemporary Art (MMCA), Korea has been operating as one of the executive agencies since 2006. The purpose of this study is to examine rather the MMCA’s turning into an executive agency and remaining as such has allowed better acquisition of operational autonomy. In the first section, the logic behind executive agency system, and the background of how and why such method was incorporated in Korea are examined. Then for the case analysis, MMCA’s managerial and art collection regulations from 1999 to 2013 are reviewed to discern how the autonomy of museum director actually have improved since the agencification. The result of study shows that the newly legislated museum’s managerial regulation (2006) stipulated director’s managing right in organization, personnel and budget, which greatly restricted leadership; director’s power was limited to autonomously forming temporary organization and managing contract based public servants. In art collection regulation, director gained more right in recommending and ultimately selecting art works to be collected immediately after the agencification. Hereafter, the reforms of art collection regulation emphasized on bringing more outsiders’ input and actively utilizing committees(newly creating them or increasing the number of committee members) for recommending, selecting and deciding on the optimal/fair price for the artworks. This study concludes that the agencification of MMCA was not an institutional change with a decent improvement of operational autonomy but a way to shift more responsibility to the director of MMCA. This change left the museum vulnerable to government influence and outside pressure, therefore not necessarily beneficial to the steady and continuous growth of professional performance.