The origin in the administrative decisions that address the general employee is to be issued in a way that enables him to acquire the rights by being in public legal centers or self centers that shall not be subjected to except by the way specified by the law. This legislation requires respecting the acquired rights and the commitment to apply the legislations with a direct impact on the current legal links in force, even if they were generated before that date. The administration may not allege the existence of a public interest to prejudice the acquired rights of its employees or apply its decisions to individual legal situations that arose prior to its enforcement. If the administration may do so, the employee would not be assured of his legal position, and it is not fair for the individual legal situations to collapse while having arisen correctly and stabilized legally by applying new administrative decisions that modify or nullify their results, and this is the essence of the principle of job legal security. On this basis, this study was made by research and scrutiny in the substantive and practical aspects of the principle of job legal security in Omani legislation. The introductory research in it examined what is the principle of legal security in terms of its definition and identification of its elements, while the first chapter was dedicated to talk about the principle of respecting the acquired rights and its impact on protecting the legal security of the general employee. The second chapter of the study dealt with the principle of non-retroactivity of administrative decisions and its role in protecting the legal security of the general employee, all according to a comparative analytical descriptive approach that was concluded to a set of results and recommendations that we hope to implement whenever possible.