This paper aims at the examination on the fallacy of the name of ‘Dadaepo-gaeksa’. The results are as follow: The so called ‘Dadaepo-gaeksa’ was one of the official buildings of Dadaejin, the naval forces in the late period of J osun dynasty. The building was moved to Molundae near the original site in 1970. And two years later, it was designated as a cultural asset. However it’s real name is ‘Dadaejin-dongheon’, because Dadae-jin gaeksa was demolished about the time of the foundation of Dadaepo-elementary school. Otherwise, Dadae-jin donheon was used as a school building from 1904 to 1970. Futhermore, the architectural style of the existing building is different from the general gaeksa’s in the period of J osun dynasty. Therefore, the name of Dadaepo-gaeksa needs to change into Dadaejin-gaeksa and to restore as its original style.