The Thesis tackled the issue of incorporate governance of the Joint Stock companies in the Sultanate of Oman which appeared in the Sultanate and in most of other countries as result of the unstable financial conditions resulting in financial ruining or destructions of most of East Asia , Latin America ,Russia ,Britain &U.S.A companie as well as the instability of Muscat Security market, and that was in 1998. The Thesis is divided into preliminary chapter dealing with & treating the concept of incorporate governance and the historical development of companies in the Sultanate of Oman , focusing on the unique internal position of the Sultanate through the amendment of companies law NO. (4) for year 1974, the latest amendment was issued in 27/11/2005, in addition to the two decisions and the Circulating letter issued by the Public Authority of Capital Market along with the regulations of managing & controlling the code of corporate Governance of MSM listed companies issued by the Circulation letter NO. 11 for year 2002 and its amendments , issued in 3/June 2002 . In addition to the preliminary chapter, The Thesis includes three other chapters the first one deals with the formation of the Board of Directors, whereas the second chapter deals with surveillance of Board of directors works. In the third chapter we tackled the civil and criminal responsibilities of members of Board of directors . The Thesis finishes with many findings and suggestions that may contribute to enable the Public Authority capital Market in protecting small Business investors and control the work in managing the Joint Stock companies.