The function of communication in the domain of public relations is one of the main factor in public relation activities. The role of communication represents and reflects an organization goals and vision which enable them to communicate with the audience internally and externally. The role of communication is vital in the public relations field because it is the main tool used in delivering messages to the audiences. This study aims to identify the nature of the communicative function in the field of public relations in both the public and private sector institutions in the Sultanate of Oman, by identifying the means of communication used, and the extent of using of the traditional and new inedia in their relationship with the public. The study also aims at identifying communication patterns used by both the public and the private sectors and the importance of PR functions and objectives in these institutions. The study also seeks to identify the role of planning and research in the cominunication process and the role played by these vital functions in the communication process in these institutions. Finally, this study will provide recommendations to increase efficiency in communication in public and private sectors in Oman. The importance of this study relies on the fact that the study addresses the role of communication in public relation departments in public and private sectors in Oman for the first time. Furthermore, the study results provide data which can be used for future research and work to measure and compare transformation in communication role for public relations in different organizations in Oman, Likewise, it provides formation that can be used to improve the role of communication for public relations departments in both sectors. This descriptive study focused on specific phenomenon and used questionnaire to collect data and information. In addition, it used random sample in selecting organizations in both government and private sector, The study shows that the percentage of males in leadership positions is higher than female in public relations departments in both the private and the public sectors. In public sector, 80% of leadership positions are occupied by males. In contrast, male's percentage in private dropped to 65%. In addition, this study shows that the age category of leadership positions in public relations departments in the public sector is from 25 to 36. In details, 10% are less than 25 years old and 20% are more than 45 years old. In the private sector, the highest percentage is in the age category of 25 which represents 70%. On the other hand, 20% are less than 36 years old. The lowest percentage in the private sector is 10% ,the age is less than 25 years old. The results show that most of the employees are bachelor degree holders in both private and public sectors. In public sector the percentage reaches 65% of the employees and 80% in private sector. The second qualification is secondary school certificate. In public sector 25% of the employees have secondary school certificate and 10% in the private sector. However, employees with master degree are 5% in both sectors. Additionally, the results show that the employees in the public relation in government sector basically belong to three study majors: 35.3% in public relations, 40% in management and 6.7% in linguistics. On the other hand, private sector has 42.1% in management major, 31.6 in public relations and 5.3% in media, journalism, marketing and linguistics. Results show that there are new communications tools widely used by government and private sectors .Similarly, both sectors use variety of tools to communicate with internal and external audiences. However, results show that private sector is highly using different communication tools including social media. Also result indicate that planning and scientific research are more remarkable in private sector than in public sector. To illustrate: results show that 45% of public organizations practice planning, whereas 95% of private sector practices planning in public relations. Besides, results show that 85% of private sector is conducting scientific research and only 20% of the public sector is doing so. In summary, this study shows that there are many challenges facing communication work in both sectors. Some of these challenges are related to human resources, budget assigned to accomplish the activities and other challenges are related to the lack of support from top management and other organizations departments.