We have briefly looked at the history of the study of Jagyeongnu (自擊漏, automatic striking clepsydra) in the modern and contemporary peri- od of Korea so far. The study of Jagyeongnu is divided into before and after as of 1980. Prior to 1980, Hong Yi-seop and Jeon Sang-woon conducted ba- sic research. During the Japanese colonial period, Hong Yi-seop studied Jagyeongnu as a “pride of the nation” in a nationalistic perspective. And after liberation, Jeon Sang-woon tried to reveal “Korean creativity” based on thorough literature research. Research on the restoration of Jagyeongnu was carried out in the 1980s. It took about 30 years to restore and install Jagyeongnu at the National Palace Museum in November 2007. This process is divided into three periods. The first (1980-87) was a collaborative re- search period between academia and the government that sympathized with the need for research and restoration of Korean scientific and cultural properties in the early and mid-1980s. The second (1988-96) was a pro-pulsion period for the restoration of Jagyeongnu, which was promoted as part of the Gyeongbokgung Palace restoration project. The third period(1997-2007) was a restoration installation period in the National Palace Museum of Korea.