内婚制〈Endogamy〉是一种约束男女必须在某一特定社会阶层以内，或某社会团体中，或宗族内，或家庭内，选择配偶的婚姻制度。

近亲婚姻是亲属间的婚姻关系。

Endogamy is the practice of marrying within a specific ethnic group, class, or social group, rejecting others on such a basis as being unsuitable for marriage or for other close personal relationships.

Endogamy is common in many cultures and ethnic groups. Several ethnic religious groups are traditionally more endo****us, although sometimes with the added dimension of requiring marital religious conversion. This permits an **** marriage, as the convert, by accepting the partner's religion, becomes accepted within the endo****us rules. Certain groups, such as Orthodox Jews, have practised endogamy as an inherent part of their religious beliefs and traditions.