The problem of juvenile dealing with the law is one of the problems surfaced in the effort to protect and to fulfill juvenile's rights in Indonesia. Currently, the problem is handled with Law No. 11 of 2012 concerning the Juvenile Criminal Justice System (SPPA) which regulates the judicial process for juvenile in conflict with the law, including juvenile in conflict with the law, especially regarding their assistance in the court. The existing problems show that the SPPA Law does not reflect the value of justice on the legitimacy of legal acts of juvenile in conflict with the law. This study uses a socio-legal research approach with data sources, namely primary data obtained in the field and relevant literature as a secondary data. The data analysis used was a descriptive-analytical method. The results the author's research shows that the protection of the legitimacy of juvenile's legal acts in conflict with the law in the juvenile criminal justice system in Indonesia has not shown the value of justice optimally because not all juvenile who undergo a judicial process in child criminal cases receive assistance from their parents or biological parents them, it is not uncommon for many parents to feel embarrassed to accompany the criminal justice process for their juvenile. From this, efforts are needed to reconstruct the legality of legal acts of juvenile, namely reconstructing and adding new constructs of Article 1 point 18 with new constructions and adding one new construction as point 18a.