The thesis is entitled "Implementation of Registration of Transfer of Ownership Rights on Land due to Buying and Selling in Kupang City" with the aim of the research being that the author hopes to know the Implementation of Registration of Transfer of Ownership Rights on Land due to Buying and Selling in Kupang City and to know what obstacles are faced in the Implementation of Transfer Registration Land Ownership Rights due to Buying and Selling in Kupang City. The research carried out by the author is empirical research, namely the data collection used in this research is literature study and interviews and analyzed qualitatively. Based on the research results, the implementation of the registration of the transfer of land ownership rights due to buying and selling in Kupang City, especially in Maulafa District, Sikumana Village and Alak District, Batuplat Village, was carried out in accordance with the local Land Office regulations, but several things also happened, such as the making of a Sale and Purchase Deed which should have been made. by PPAT, in fact, several respondents made deeds under the hands of parties involved in the legal action of buying and selling land ownership rights.