This study primarily aims to illuminate the characteristics of Meoreum in Korean traditional fitting system according to the respective types and its periodical changes. Using the research findings as a chronological indicator by which to estimate the construction date of the building is the secondary purpose. In this study 42 of Byeoldang and pavilion architecture remaining in Yeongnam district were examined through the field surveys and methods of documentary research. The research results are as follows. First, Meoreum, which is located below the windows or doors, provides protection against the outer wind and has the function to prevent some warm air of the room from flowing outside. Second, Meoreum was recorded as Yoeum(了音), Woneum(遠音), and Maleum(末音) in Yeong-geon-ui-gwe (營建儀軌) of Joseon period. While Yoeum(了 音) was used in Yeong-geon-ui-gwe (營建儀軌) of 1776 and 1856, Woneum(遠音) had been also used continuously since the year of 1800. The word, Maleum(末音) can be seen in Lim-won-gyeong-je-ji (林園經濟志), published in 1827. Woneum(遠音) and Maleum(末音) seem to be the Yi-du(吏讀) types of expression of Meoreum which is being extensively used now. Third, the kinds of Meoreum can be classified as TohMeoreum, TongMeoreum, TongpanMeoreum, and J janeunMeoreum. TongMeoreum and TohMeoreum were mostly used at the front part of Ondol-rooms, the backside of main floor called Daechung(大廳), and at the space between Daechung and rooms in the Pavilions and Byeoldangs(Annexes) that had been built in the early Joseon dynasty. TohMeoreum was usually used at the bottom parts of windows between Daechung and Ondol-rooms. TongpanMeoreum was mainly used in the mid-Joseon period and relatively high height was the distinctive feature of Meoreum at that time. J janeun Meoreum, used mainly in the late Joseon dynasty, has become lower and lower gradually in height since 19th century, so people could enter the room through the windows(fittings). Such changes in Meoreums types has brought about the flow of human traffic directly from Toenmaru, narrow wooden porch running along the outside of a room to Ondol-rooms.