The aim of study is to identify The Leadership styles of primary school principals according to ("Reddin's") theory and its relationship to teachers' self-efficacy in the Dakhiliyah Governorate in the Sultanate of Oman To achieve the objectives of the study, the descriptive correlative approach and the questionnaire was used as a tool for the study (350) teachers from Dakhiliyah Governorate. The study reached a set of results, namely: the degree of practice of principals of basic education schools leadership styles according to the three-dimensional theory of "Reddin's" in Al Dakhiliyah Governorate in the Sultanate of Oman came with medium degree practice.also The study found that the level of teachers' self-efficacy came to high level, It was found that there is a positive relationship between the practice of school principals of administrative leadership according to Reddin's theory and the self-efficacy of teachers, that meaning the higher degree of school principals' practice of leadership styles according to Reddin's theory, the greater the teachers' self-efficacy and vice versa In light of the results, the study recommende a set of recommendations, namely: The administrative supervisors of the Performance Development Department in the Directorate of Education should strive to train school principals on the dimensions of Reddin's theory of administrative leadership and how to implement its strategies in the modern school. And to the need for the school principal to develop a professional development plan for teachers to help them raise their leadership level and how to employ the dimensions of leadership in the educational field.