The aim of this study was to raise the level of the school principal's practice in the professional development of teachers in Al Dahira in Oman Abdullah bin Said bin Salem Al Badi The descriptive approach was used and a sample of 119 principals, assistants and early teachers was formed. In order to achieve the objectives of the study, the researcher used the questionnaire, which verified its validity and stability, where the goal was to answer the following questions: 1. What is the degree of the school principal's role in professional teacher development in Al Dahira in Oman? 2. Are their differences of statistical significance at the level of significance (0,05) for the degree of the headmaster's practice for his role in the professional development of teachers according to the gender variables, scientific qualification and job? The main results of the study are as follows: 1. The degree of the school principal's role in the development of teachers professionally in terms of the tools of the study was in a very large and large degree. 2. There were no statistically significant differences at the level of significance (0,05) for the degree of the school principal's role in the professional development of teachers according to the variable of the scientific qualification. For the gender variable, differences were only at the pivotal level of human relations and evaluation in favor of females. As for the function variable, the differences in the focus of technology employment and management of the educational process were for school principals. In light of the findings of the study, a number of recommendations and suggestions were presented. The most important of these studies are the following: to promote good and effective school principals to professional development programs that provide teachers with their role in the professional development of teachers by encouraging them to implement and reward them for their efforts, Schools to provide high-quality professional development programs and the need for school principals to take into account the actual training needs of teachers in the preparation of training programs and their involvement in the planning, design, implementation and evaluation of these programs.