Direct relatives cannot marry, and those who do not meet the conditions for marriage are as follows:
 （1） A person who has a marriage relationship with a third party and whose marriage relationship has not been terminated.
 （2） Those below the age of marriage: men were earlier than 22 years old, and women were earlier than 20 years old.
 （3） Suffering from physical defects that should not be married. Persons suffering from leprosy who have not been cured or who suffer from other diseases that are considered medically unfit for marriage are prohibited from marriage.
 （4） Marry a relative who has direct blood relationship and collateral blood relationship within three generations.
 （5） It is not said that people who have lost sexual capacity cannot marry, but they must tell each other in advance.
 [Legal Basis]
 In Article 1048 of the Civil Code, marriage is prohibited for direct relatives by blood or collateral relatives by blood within three generations.