This paper serves to analyze discourses on concubine at the beginning of the modernization era or during the enlightenment period of Korea. For this analysis, the estimated time frame of the enlightenment period will be from 1860 through the time when Korea was annexed into Japan, which was in 1910. The discourses appeared in newspapers and Shinsoseol which are the text of this study have been analyzed with the qualitative research technique. The major conclusions that are derived from the study are as follows: First, intellectuals during enlightenment period of Korea, criticizing concubinage, tired to establish the monogamous relationship and they argued that it should be the prior condition for Korea to enter into the civilized society. Second, the concubinage was criticized in the point of the newly established view. The criticism was on double sex ethics, applying different ethical standards to men and women and the prohibition of wifes jealousy of concubine. Third, intellectuals during enlightenment period of Korea were tried to do away with concubinage by enforcing the discrimination between wife and concubine. But the efforts resulted in making concubinage personal problems. Also consciousness based confucian ethics including female virtues was forced to be followed in ordinary affairs while concubinage was criticized in the point of the view of western ethics based consciousness. The huge differences between two ethics consciousness resulted in serious conflicts in family.