Sexual violence against children is a serious crime that causes long-lasting physical, psychological, and social impacts. Therefore, it requires an effective mechanism for restoring victims' rights, one of which is through Restitution, a modern criminal law instrument designed to restore victims' conditions as close as possible to their original State. However, in law enforcement practice, the implementation of Restitution often encounters obstacles, particularly when perpetrators fail to fulfill their restitution payment obligations as ordered by the court. This is exacerbated by the lack of comprehensive and synchronized regulations between Law Number 35 of 2014 concerning Child Protection and Law Number 12 of 2022 concerning Crimes of Sexual Violence regarding substitute sanctions for Restitution. This study aims to examine the legal regulations regarding substitute sanctions for Restitution for child victims of sexual violence, analyze the gaps in norms and legal dualism in both laws, and assess their implications for the fulfillment of victims' rights and legal certainty. Using normative legal research methods through statutory, conceptual, and case-based approaches, the research results indicate that although Restitution has been recognized as a right of child victims, neither the Child Protection Law nor the Sexual Violence Crime Law explicitly, clearly, and operationally regulates substitute sanctions for Restitution if the perpetrator is unable or does not act in good faith to pay. This creates a legal vacuum, resulting in the suboptimal fulfillment of victims' rights and potentially creating legal uncertainty. Therefore, it requires harmonization and regulatory reform to ensure the protection and restoration of the rights of child victims of sexual violence in a just manner.