Title of the dissertation: The children's surname in the different forms of ''status filiationis''. In the study of this subject we have focused our attention on the judgments of the Constitutional Court in which it has been identified the recognition of a ''superior'' interest to the personal identity of the children, in the attribution of the surname, also in the various forms of status filiationis. The right to the personal identity has been recognized for the first time with a judgment of the Cassation of 1985 and on 1994 the boundaries were established with the Constitutional judgment number 13 including also the use of the name, which is defined by the Court as ''the first and the most important element which define the personal identity''. The Judge of the Laws, since the judgment n. 13 of 1994, followed by judgments nr 297 of 1996 and n. 120 of 2001, has therefore contented the right of the subject to maintain the surname which has became independent distinctive signed of the personality. Therefore, maintaining through the surname the identity owned even when events involving the changing of surname have happened. With reference to the relationship between the personal identity and the surname, the doctrine there are orientations highlighting the limits of the private function of the surname, highlighting also the public interests to the conservation of the surname. Furthermore, we have been focusing on the experiences of the foreign countries in order to compare the different disciplines adopted which have been related with the express principles of the European Court for the Human Rights. In the end we have paid attention to the attribution of the surname for subjects with two nationality with reference to the judgment of the Court of Justice of 2 October 2003, which was invested of the matter, fixing the principles of coordination between the internal disciplines. The key of interpretation of Family law is identified in Article 2 of the Constitution, as the family, in its social aspect and in its juridical reflex, is tightly united to the existence, the dignity, the personality of each of its components. In the valuation of the same interests that rise in the family community assume particular importance the interest of the minor and in the same time the role of the Judge in the valuation of this interest (Articles 250 paragraph 4, 251 paragraph 2, 284 paragraph 1 Civil Code). The interest of the under age is identified also with the reaching of personal autonomy and of judgment on matters of strictly personal nature, (Articles 262 paragraph 2, Civil Code; 250 paragraph 2, Civil Code; 284, paragraph 4, Civil Code), as long as the minor's psychophysics integrity and his personality are protected. The constitutional discipline of the family is strictly linked to the fundamental principles stated in Constitution articles n. 2 and n.3, with the first, recognises the close link between personality realization and the safeguard of the social formations, the second as public order principle. The surname discipline, with the aim to protect the family unity through the imposition of the father surname, rejects a direct application of the above mentioned principles. In the light of the above, it is therefore noted, that the legislator provided for acts in order to attribute the surname in minor and specific circumstances such us underage adoption (l. 184/1983) and of age (art.299 c.c.) and for natural child recognition (art. 262 c.c.), whereas in the hypothesis of legitimate family, the surname discipline is still ruled by pater legem custom which is not susceptible of Constitutional legality control and in accordance to which, the legitimate child acquires his father surname in accordance with a not written rule to safeguard the family unity. It is necessary that the surname is detected in accordance with the rules stated by the law, but those rules also have to leave to the private autonomy a limited preconceived choice, (as for instance when the natural child of age is recognised by the mother, who may subsequently decide whether to add or substitute the father surname). It is for this reason that the conventions which regulate some aspects of the family life including those related to the children gain even more importance, with ample space to the possibility for the parties of negotiation; whereas the legislation fixes general principle and adopts the function of dictating the limits of the autonomy, and in residual way, intervenes in the hypothesis of the lacking of fulfilment spontaneous or contrary. In the system of 1975, it is certainly present the knowledge of a new physiognomy of the family which has became place of search for the agreement and than of performance of the autonomy of negotiation, for which it has been recovered in the familiar context the category of the private autonomy and of the juridical agreement, largely discussed and contested for the regulation of the personal relationships. Many European countries prescribe since long time ago rules of assignment of the surname more abiding with the principle of non discrimination between the spouses. From the comparison between the experiences of some countries such as Spain, France, Germany, it has shown how, in countries such as Spain, the introduction of the Reform of the Surname, the change is justified on the basis of the need of adjusting to the principle of EC Law, which prescribe the elimination by all the member States of all the discriminations based on sex and the adjustment to the Judgment of the Court of Human Right, which has confirmed this principle.