Yang, Young-hee. 2007. A Study on Setting the Degree of Politeness of Korean Language in the Sixteenth Century. The Sociolinguistic Journal of Korea 15(2). Politeness is an important feature in Korean language and it has been studied actively. But it can be said that the study of Politeness in the sixteenth century does not exist because the century has often been tied with the fifteenth century, so that research on this field has followed that way. Nevertheless, there are many differences between the fifteenth century and the sixteenth century. Thus it is necessary to study each field separately. Focusing on this view, this investigation is to divide the forms of Politeness and these are the results. The degrees of Politeness in the sixteenth century are: polite formal style―polite informal style, and impolite formal style―impolite informal style. Considering each style with certain examples, firstly, 'nayida, nayitga, showshyeo' forms are the 'polite formal style' and these were used between people in different social ranks, such as 'servant to king, apprentice to master, offspring to parent'. Secondly, 'naengyida, naengyitga/ naengda, nitga/ nae, singa, so' forms are the 'polite informal style' and these were used to express intimacy. In more detail, 'nae, singa, so' forms were used in family relations, not in social relations. Thirdly, '-da/-nda/-ra' forms are the 'impoliteformal style' and these were used to make differences of social ranks definitely. Lastly, '-ra/-ga(go) pattern, -(ni)ri' forms are the 'impolite-informal style' and these were used to make more amiable relations in different social ranks and narrow the emotional distance.