The purpose of this study is to analyze and find weaknesses in the regulation of the synergistic implementation of the duties of the National Narcotics Agency (BNN) and the National Police (POLRI) in Narcotics Cases and how to reconstruct the law on the synergistic implementation of the duties of the National Narcotics Agency and the National Police in Narcotics Cases based on the Value of Justice. The method used in this study is a normative-juridical approach that uses a constructivist paradigm. The results of the study indicate that the weaknesses of the Synergy Arrangement for the Implementation of the Duties of BNN and POLRI are that they have not been regulated in the realm of the Act or other statutory regulations. However, at least in article 70 c and article 84 the regulation of the authority of the BNN and POLRI has been regulated but in need of communication factors, proper recruitment of investigators, and rules that do not overlap, therefore Reconstruction is required in Law Number 35 of 2009 Article 70c; By adding the word "mutually" Coordinate with the Chief of the Indonesian National Police in prevention and eradication. "And synergize in every activity related to both". Then in Article 84; wherein conducting investigations into the abuse and illicit trafficking of Narcotics and Narcotics Precursors, the investigators of the Indonesian National Police shall notify in writing of the commencement of the investigation to the BNN investigators and vice versa, "And carry out work synergies by both". By adding the word synergy, it means that there are efforts that bind the occurrence of good cooperation in the form of an MOU between BNN and the Police.