This research focuses on the language-use of the family members from the multicultural household that consist of Japanese wife and Korean husband residing in Seoul, Kyoenggi, and Chuncheon. The collected data includes the language-use of the wife, the husband, and the children as well as the entire household. Such data is analyzed according to the wife’s age, level of education, and number of years of residence in Korea. As a result, the research has concluded that the language-use of each household differ more by the age rather than the level of education. Although the majority of the wives in all ages mainly speak both Korean and Japanese, the use of all three languages, Korean, Japanese and English, has increased as their education level increased. Furthermore, while the language-use of the husbands differs by the age, the use of two or three languages has increased as the education level of their wives increased.
Lastly, as the majority of the children in all ages mainly speak both Korean and Japanese, the use of two or three languages has increased as the education level of their mothers increased. In conclusion, there exists a correlation between the mother’s education level and the children’s language-use. Moreover, the use of both Korean and Japanese by the children has increased as their length of residence in Korea increased. Therefore, another correlation exists between the length of residence in Korea and the children’s language-use.