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 $JjaneunMeoreum$. $TongMeoreum$ 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. $Jjaneun$ $Meoreum$, 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 $Ondol-rooms$.