Corporate Governance is a very extensive business because all interests - influential groups from shareholders to banks, investment funds must be met. In addition to management there is a problem that can lead to disagreement between managers who are in charge of running corporate and equity holders who invest in the corporation. Many models of corporate governance have evolved in history, so today there are two corporate governance systems. Closed or continental system in which representatives of Germany and Japan are open or market systems in which the United States and the United Kingdom are representatives. The significance of the supervisory board in corporate governance is that it represents a link between shareholders (shareholders of the stock) and managers who manage the joint stock companies and increase the value of the company. Agency theory clarifies, describes and formalizes the relationship between agent and principals. This relationship arises when one party (principal) engages the other party (agent) to do some business. The agency relationship is defined by the relationship of the owner as the principal and the manager as an agent, that is, the situation where the owner of the company delegates the management of the enterprise to the manager. Agency theory, applied in the domain of corporate governance, has some limitations. It shows that principals, as a group, share common interests but individual corporate investors (companies, institutional investors, banks, individuals, employees as shareholders and others) do not share the same goals.