Change in sexuality is one of the important subjects that caused for founding new jurisprudence and legal subjects. Among these subjects, we can refer to permit or non permit for doing this and its further relevant jurisprudence and legal effects. In the present article, we want to considered these two subjects and clear that if such an action made on a person who have physical disorder in genital organs, it will legally and permissible , otherwise , have no justified definition from law stand point. About mental neutrality (who have no disorder in genital organs but due to mental problem demand for change), there is three theories as presented: 1-Fixed permission 2-Fixed forbidden 3-Conditional permission. The final theories have more protest and selected by majority of theoritian. According to view points of great jurisprudence, persons who change his/her sex, shall be benefitted from real sex share in issues including heritage, blood money, limits, asked for witnesses, marriage portion, but in law rules observing and obligation shall be followed superficial basis. In subjective Iranian law, who change his/her sex according to medical standards, have right to demand for amendment of identification card.