The research aims to explain the founders' responsibilities in shareholding companies. Since the founder is the basis and the key element in a shareholding company due to their efforts in establishing the company, therefore it is important to refer to the founder's duties and roles in establishing the shareholding company and accordingly the responsibility resulting from violating foundation rules. The research includes a number of questions, namely: 1. What are the definition and importance of a shareholding company? Y. Who is a company founder in general and in particular? 7. What are the responsibilities and duties of company founders according to the Oman Commercial Companies Law? {. What are the penalties resulting from founders' failure to fulfill their duties? Those questions have been answered via dividing the research into an introductory section in which the researcher tackles the shareholding company definition, characteristics and importance locally and internationally. Then the first section, in which the researcher tackles the founder definition in law and jurisprudence in general and particular and accordingly defining founder duties and responsibilities in establishing the shareholding company. While the third and last section of the research includes the cases in which the founders responsibilities arise and the resulting consequences both on civil and criminal sides, In the research conclusion, the researcher highlights the most important outcomes he reached in respect to the responsibilities of shareholding companies founders according to the Oman Commercial Companies Law No. (4) Of 1978, followed by a recommendation to amend and add some provisions that are essential to define the responsibilities of the founder in a shareholding company.