In the Republic of China, "concubine" was not called concubine, but became a man's "family member", and was uniformly and decently called "concubine" to the outside world.

"Ten Years Court Explanation No. 647" states: "Taking a concubine is not a marriage, and there is no bigamy." "Twenty Years Court Explanation No. 735" states: "Concubine Although it is not stipulated in the current civil law, since the concubine and her parents live together in the same household for the purpose of living together permanently, they should be regarded as family members in accordance with the provisions of Paragraph 3 of Civil Code 1123." "Judgment No. 636 of the Year 22" stated: "There is no provision for concubines in the kinship code of the Civil Code. After the kinship code of the Civil Code is implemented, if similar behavior occurs, it is considered adultery, and the wife can apply for divorce." If the wife expressly admits or acquiesces to the act of taking a concubine, the wife shall not use it as a request for divorce." During the Republic of China, especially after the May 4th New Culture Movement, women's rights were proposed and equality between men and women was advocated. Monogamy was truly implemented and was included in the Marriage Law.