The article is devoted to the study of the problems of the ownership of the plaintiff and the defendant as parties to a land-property dispute in the current law enforcement practice of courts of general jurisdiction. The author emphasizes that the primary task of the judicial branch of government and a specific court as its representative is to correctly determine the subject composition of the case, the subject of which is the resolution of a land and property dispute. Achieving the specified task has two main consequences: obtaining legal protection of the violated, unrecognized or disputed right by the proper “offended” person and placing responsibility for the committed encroachment on property rights on the actual violator. The article analyzes the procedural institution of replacement of an improper defendant as a mechanism designed to ensure the implementation of the principle of ownership of the parties to the dispute in the civil process. In particular, the author drew attention to the fact that in the judicial practice of courts of all instances, the terms “proper plaintiff” and “improper plaintiff” are used, the definition of which is not contained in the current civil procedural legislation. In addition, the article analyzes the judicial law enforcement practice formed in the part of replacing an improper party in cases for the resolution of land and property disputes and formulates relevant conclusions regarding the ambiguity of the positions of courts of general and administrative jurisdiction in this matter. The author conducted a comparative analysis of the legal regulation of the institution of replacement of the proper party in a dispute under civil and administrative procedural legislation. Based on the results of the research, the author outlined the scientific and practical aspects of the investigated issues in this field of civil procedural law. In particular, the author comes to the conclusion about the inconsistency of the legislator’s vector regarding the development of an effective procedural mechanism for the protection of the rights of subjects of land legal relations, which in turn creates prerequisites for possible abuse of the court’s procedural powers.