Marriage is the legitimate relationship between a man and a woman. With its root going back to humanity’s creation, marriage affects the life of humans permanently. Some men and women are eternally forbidden to unite in marriage; that is, it is considered prohibited for them to get married to one another. The Imamiyyaand Zaydiyya jurisprudential systems, as two known schools of law in Shiism, have similarities and differences with respect to such prohibitions. Prohibition due to blood relationship(relationships caused by legitimate marriages, illegitimate relationships, blood relationship caused by artificial insemination, the ninth divorce, illegitimate relationship with a married woman, heinous acts, and so on) exist in the Shiite jurisprudence and law, which constitute the common ground between the Imamiyyaand Zaydiyya jurisprudential systems. On the other hand, prohibition due to marital relationship such as relationship by marriage, foster relativity with the fulfillment of its special conditions, Li’an (separation by invoking curse) and illegitimate sexual relationships are among certain forbidden instances in the Imamiyya jurisprudence, but the Zaydiyya jurisprudence disagrees with it in some cases. In this regard, Civil Rights in Iran, as derived from the basis of the Imamiyya jurisprudence, is in some respects different from Civil Rights in Yemen, as developed under the influence of the Zaydiyya jurisprudence.