The objective of this study is to identify the expected authority delegation of the schools principals according to the educational literature, and the actual authority delegation of the secondary schools principals in the Sultanate of Oman from their assistants and first teachers points of view, and whether these points differ or not according to the job title, sex, experience in schools, and educational regions. The sample of the field study consisted of (111) assistant principals and (216) first teachers, who were randomly selected from male and female assistants and first teachers working in five regions {Muscat, Al-Dakhelyyah, Al-Batinah (North), Al-Batinah (south), AlSharqyyah (south)}. The region have been selected from ten educational regions in the Sultanate. The study has determined in its theoretical background the concept of principal's authority delegation, the effectiveness of delegation, the procedures of delegation, and the obstacles of delegation. On the other side, the results of the field study indicated as perceived by most assistants and first teachers, that principals perform the basics of delegation and practice it to a considerable extent. The result also indicated as perceived by most assistants and first teachers, that the real authority delegation of principals faces obstacles that appear in a medium degree. In addition, the results of the study illustrated that there were no statistical significant differences at (oc= 0,01) between assistants and first teachers in the basics, practices and obstacles of the principals' authority delegation attributed to the job title. The results also indicated that there were no statistical significant differences at (oc= 0,05) between assistants and first teachers in the practices and obstacles of the principals' authority delegation attributed to the sex. However, the results illustrated that there were statistical significant differences at (oc= 0,01) between assistants and first teachers in the basics of the principals' authority delegation due to the sex in favor of females. In addition, the results of the study illustrated that there were no statistical significant differences at (oc= 0,05) between assistants and first teachers in the basics, practices and obstacles of the principals' authority delegation attributed to the experience. . The results indicated that there were no statistical significant differences at (o= 0,05) between assistants and first teachers in the basics and practices of the principals authority delegation attributed to the educational region. However, the results illustrated that there were statistical significant differences at (o= 0,05) "in the obstacles of the principals' authority delegation due to the educational region between Al-Batinah (North) and Al-Batinah (south) in favor of Al-Batinah (south). Finally, the study concluded with a number of recommendations and suggested studies.