Indonesia is ranked 15th (fifteenth) as the largest country in Indonesia, and the largest population is ranked 4th (fourth). This makes such a large area of land as a very high asset for the people. In order for society to be created, Indonesia as a legal state makes laws regarding this matter. Indonesian Law Number 5 of 1960 Basic Agrarian Regulations (UUPA) finally emerged, with various objectives, one of which was to ensure legal protection for their rights regarding land in the community. However, of course there are so many parties in society. There will be problems that arise, one of which is land theft or taking other people's rights without the rights owner's permission as in Judicial Decision No.249/Pid.B/2022/PN Jkt Brt. There are quite a few such cases, so Technical Instructions No.01/JUKNIS/D.VII/2018 (JUKNIS 2018) was made. The research method used by the author is normative juridical, this is because the author examined the relationship between UUPA and JUKNIS 2018 with Decision No.249/Pid.B/2022/PN Jkt Brt. The research results show that there is regulation and implementation in handling land mafia cases, both in the form of prevention and eradication. In terms of evidence, there is not much that can be taken directly if you only look at the decision. The UUPA itself does not discuss the land mafia in a significant way, and several sources outside the decision are needed so that the 2018 JUKNIS can be seen whether it is working or not.