Land has a very importat role for human life, because land is the main foundation of all activies carried out by humans, land is an important aspect of human life. So important is land for human life that everyone always wants to try to own and dominate over the land. With thism land disputes can arise in the community, due to the increasing need for land, as in the case of the Tangerang District Court Number: 968/PDT.G/2017/PN.TNG. this thesis uses the approach taken, namely the legal approarch, the case approach, the conceptual approach. In this thesis, the author discusses how the implementation of mortgage deed if the seller dies. In this decision ownership rights over lans use right, where there is an injustice of the seller to the buyer. With the Basic Agrarian Law and Government Regulation No 24 of 1997 all about land issues already exist in the Act. With this we all as sellers/buyers must carry out their obligations.