Abstract
The purpose of this research is to analyse the changes of ground level of Sungnyemun, the South Gate of Seoul City, and the principles of arch scale through the investigation based on the old records in Joseon dynasty. The result of this research is as follows: 1) The ground level of Sungnyemun, refers the level of foundation stone which was confirmed as original which is verified through the excavation conducted in 2005, maintained 1m's elevated level in 15~16 century and its elevated date presumed in King Sejong's reign(1418~1450). 2) The ground level of Sungnyemun is closely related with the royal funeral ceremony. 3) The width and height scale of Sungnyemun arch is about the ratio of 1 to 1. 4) During the Joseeon dynasty, Sungnyemun was referred as standard of other city wall gate. And it has similar architectural characteristics with Heunginjimun (or East Gate) of Seoul and Hwaseong Janganmun.