This research aims to find out about Indonesian state institutions that play a role and authorized when conducting maritime diplomacy in combating illegal fishing practices in the Malacca Strait in 2014. To show the public that the success of a diplomacy conducted by the state lies in the legal authority and in the infrastructure owned by the institution. This research is a qualitative research that explains why maritime diplomacy conducted by Indonesia in handling illegal fishing practice is not effective. The method of this research is library research that to collected the data from libraries, books, journals, articles, print media, electronic media and websites. The results of this study indicate that the regulatory synergies of Indonesian institutions have authority in securing the security in the Malacca Strait still overlapping the law policy in 2014 especially to combat the practice of illegal fishing. This has an impact on the strategy that has been set up as steps for the interests of strait security as a form of Indonesian maritime diplomacy in Malsindo Coordinated Patrol not run effectively.