The main topic of the thesis is registering of state border and adjustment of land cadastre data with the state border data for the case of Slovenian-Italian border. For this purpose, data from the official state border evidence and land cadastre data in the Republic of Slovenia have been used; additionally, archive data about evidencing of state border at the regional office of the Surveying and Mapping Authority in Nova Gorica have been used, and legislation as well as other professional literature from the study field have been studied. In the thesis, some basic terms from the study field are explained in the beginning, followed by the description of Slovenian-Italian border, including its changes through the history and its current situation. Further on, the contents of state border documentation and procedures for recording of the state border are presented, accompanied by the examples from the practice at the Slovenian-Italian border. These study cases are mostly about the adjustment of the cadastre data with the data about state borderline from the official evidence, and about the procedures for preparing new documentation about the state border. In the framework of this thesis, we tried to define the reasons for such a discrepancy between the land cadastre data and data about state border, which lead us to the conclusion, that this was mainly the consequence of digitalisation of the state border documentation and of the cadastral maps. Copying, tracing and transfer of the data among different media, formats and forms of evidence also played an important role.