The purpose of this study is to explore whether the phenomenon of both married and unmarried adults' cohabiting with their parents in Korean society is "unilaterally parasitic" on the child's side, or is "interdependent", characterized by expectation and dependence from the parent's side. As a result of this study possessing the characteristics of theoretic research, the following propensities of parent-dependent adults have been discussed. First of all, it was discovered that the ratio of adult children dependent on and cohabiting with their parents is considerable. Second, parents cohabiting with their adult children have unfavorable sociological features, such as high age, low level of education and income, and lower standards of education and income, compared to parents in normal households. Third, it was found that parent-dependent adults in Korean society maintain a relatively high rate of financial activity and stable employment-based occupation status. Fourth, it was shown that the level of satisfaction on the relationship between parent-dependent adults and their parents was discovered to be high, which is contrastive to the prediction of negative results based on some previous researches. Single adult children's age, their level of education and financial activity status, and their parents' age and level of education were deducted as variables related to the level of satisfaction of the relationship between parents and their children. It seems that the issue of married and unmarried adults' cohabiting with their parents in Korean society should be approached from various perspectives such as political, economic, socio-cultural and developmental aspects. On the basis of this fundamental awareness and several of the materials, it is pertinent that approaches to both married and unmarried adults' cohabiting with parents in Korean society should be distinguished from approaches to those in Japanese or Western society because it reflects the uniqueness of Korean society. In the phenomenon of married and unmarried adults' cohabiting with their parents in Korean society, there are several factors besides the economic factor, especially the socio-cultural factor that have the characteristics of mutual dependence between parents and their children rather than those of unilateral parasitism, in contrast with the phenomenon in Japanese or Western society. This research was aimed to contribute by establishing basic data for policy making by providing necessary information to treat the issues of instability and anxiety related to families and reflection on the matters of generations and parent-child relationships in current Korean society.