This thesis will be described the concept of the market, as well as the types of market structures. On the market are four basic market structures, such as a monopoly, monopolistic competition, oligopoly and perfect competition. These market structures differ in the number of participants, the way in which prices are formed. If in the market there is only one supplier, a large number of customers it is a monopoly, if in a given market there are a large number of suppliers and a large number of customers it is a perfect competition. In oligopoly there are few sellers; few can mean 2, 10 or 15 companies. When it comes to monopolistic competition it is a large number of the vendor that produces differentiated products. The work consists of several parts. The first part is an introduction, followed by the second unit describes the market and market structure, the basic terms associated with a particular market structure, basic features of a particular market structure and the way prices are formed in different market structures. The third section refers to the Republic of Croatia and its market, market structures that exist in the Republic of Croatia, the characteristics of these market structure and examples for each market structure. At the end is enclosed the final review, or conclusion on the overall thesis.