The natural children and the legal capacity related to them has been always a matter of controversy in many legal systems. In some legal systems such as France, homogenizing the rights of legitimate and illegitimate children is sought, while in Islamic countries, particularly in Iran, the purity of parentage is the matter in legislation relating to children. This article explains the arguments for and against the homogenizing rights of illegitimate children stating that advocates argue for homogenizing of children's rights, whether legitimate or illegitimate, with an emphasis on the principle of individualization of punishment They believe that considering some deprivation for natural children, while they normally have no role in the matter is contrary to justice and anyone should not be punished for the mistakes of others. In contrast, opponents state that the abolition of the statutory deprivation for these children is not only to the detriment of families, but it would weaken the foundation of them and cause in diminution of relative interests and also in damaging the children, who come into the existence through this way. Hence, with an awareness of the adverse consequences of failure to guarantee the generation of illegal relationships outside of the families, the Islamic legislator seeks to protect the health of generations and purity of people in the community. Because, in the Islamic religion, purity of parentage is one of the main intentions, so that many of the provisions have been issued in order to protect and preserve it.