Invalid marriage refers to the marriage of men and women who do not meet the substantive conditions of marriage and do not have legal effect in law. Invalid marriage does not belong to divorce.
Article 10 of the Marriage Law stipulates that marriage is invalid in any of the following circumstances:
（1） Bigamy;
（2） Having relatives who are prohibited from marriage;
（3） Having contracted a disease that is medically considered unfit for marriage before marriage and has not been cured after marriage;
（4） Under the legal age of marriage.
