Article 28I paragraph (1) of the 1945 Constitution which contains provisions on the principle of non-retroactivity and Article 1 paragraph (1) of the Criminal Code which contains provisions on the principle of legality, stipulates that retroactive application of material contained in laws and regulations is not permitted. In fact, there are still laws and regulations that are retroactively enforced, such as KPU Regulation Number 26 of 2018 against participants in the 2019 DPD election. Even though its implementation raises problems for election participants, the regulation remains valid and valid. The purpose of this study is to analyze the limitations of retroactive provisions on the material content of statutory regulations in KPU Regulation Number 26 of 2018. This research is a normative legal research by conducting a review of KPU Regulation Number 26 of 2018. The problem approach used is the statutory regulation approach, and the case approach. The results of the study concluded that the contents of the retroactively enforced laws and regulations are still valid and valid as KPU Regulation Number 26 of 2018. However, retroactive provisions must be regulated in a law and if they contain criminal provisions, the criminal provisions are not enforced.