The Kosachalyo was the reference book which was composed of records collected about the procedures regulating the foreign relations or daily lives of the officials or the scholars, who had no official positions, in the Yi dynasty. The compilation work of the Kosachalyo was started from the date of the compilation of the original one by U sook-kwon (魚叔權) in the 9th year (1554) of King Myongjong (明宗). Su Myongung (徐明) revised and complemented the contents of the original one in full scale, named it as the Kosashinsu(攷事新書) in the 47th year(1771) of King Yongjo(英祖). In that period, the original Kosachalyo was revised and complemented twelve times and republished. Until now, it has been said that the original Kosachalyo had been suffered the revising or complementing works six times or nine times. But in this thesis it is assured that it was revised or complemented twelve times in the period from 1554 to 1771 upon the various historical documents.