Praise be to Allah and peace and blessings be upon the Messenger of Allah and his family and companions, and after: This research tagged with: "Family security is a legitimate purpose to achieve human security" aims to show the importance of family security, and how the Sharia paid great attention to it, and stressed the need to maintain it in all psychological, health, physical, economic and moral fields as the family is the first basic social unit and nucleus, which is based on preserving it , the preservation of the human species, its security and stability, and thus the negligence of it is negligence of the human race and the human species as a whole. This research is supported by legal or Sharia ‘s texts that make it clear that achieving family security is a legitimate goal given great care by Islam, and there is no evidence of this clearer than the rotation of legal provisions either lawful or unlawful around the protection of the family: its religion, soul, mind, dignity and wealth, which preservation ot them represents the preservation of the highest levels of interests, and is called the five necessities. This research came after mentioning the legal texts supported by human studies and experiences as a source of knowledge that benefits the human race, and in support of what was stated in the legal texts of facts and results of interest that may increase the stability of the Muslim and his faith, and highlight the bright face of Sharia, away from other projects and trends that are imposed under the media noise and various pressures, despite the clarity of their destructive effects on the family and human society. The sufferings that were resulted of these devastating effects appered every where, that causes reluctance to show the truth and the beneficial and useful consequent of them, and therefore this research came as a contribution to the promotion and protection of family security as a legitimate purpose to achieve human security, where it included an introduction, seven investigations, results and conclusion. The first section included clarification of the truth of the purposes of Sharia , its sections and ranks, as the second section included confirmation that the role of women is large and important in the protection of family security and that their position in the family is responsible not hired, then the third and fourth sections indicated how Islam achieved health security and protected the family from physical and psychological diseases that may affect its members , then the fifth section showed how to achieve economic and living security, and the sixth section included a statement of how Islam achieved security for the family and protected it from extinction and weak reproduction, which endangers countries and the lack of renewal of generations resulting from the lack of births, while the seventh section dealt with the statement of how Islam achieved security for the family and protected it from crime that targets its foundation and entity. Praise be to Allah, Lord of the Worlds, and may Allah's prayers and peace be upon our Prophet Mohamed, his family and companions as a whole.