The last decades have been characterized by state intervention in the economy through the activities of various regulatory administrative entities. This dissertation aims to analyze the legal structure of Brazilian Securities and Exchange Commission (CVM) and the main instruments used to regulate Brazilian capital market. Following the North-American regulatory model, CVM is established as an independent regulatory entity. The regulation that it enacts follows the principles of disclosure policy. To fulfill its mission, CVM makes use of legislative, executive and adjudicatory regulatory instruments. This study suggests that credibility and efficiency of Brazilian capital market depend, largely, on the ability of CVM to conduct market regulation.