The purpose of this study is to retrospect the establishment process of specification of modern factory-made traditional Korean roof-tile. Its another purpose is to analyze the specification of watong(瓦桶, a wooden molding frame for roof tile making) which is recorded in the literature of Joseon dynasty. The results of this study are as follows. : First, the specification of modern factory-made Korean roof-tile that currently used was established in 1978. And it did not succeed old traditional specification. Second, in case of construction or repair of main building of palace, it was a principle to use Daewa(大瓦, the big size roof-tile). And Sangwa(常瓦, the ordinary size roof-tile) was used when needed. Also, Jungwa(中瓦, the middle size roof-tile) was used regardless of the size of group building. And Sowa(小瓦, the small size roof-tile) was used in house and wall of royal tomb. Third, it is needed to establish a specification of traditional handmade roof-tile based on the specification of watong through research of the litterateur. So, a standard draft for this was proposed. Finally, one can find the significance that this study has tried to find a specification of traditional roof-tile that can be applied to construction or repair of cultural heritage.