Since the end of the decade of 70, the siderurgical industry Brazilian vine Suffering with the massive presence of the government in the sector, therefore if resented at the lack of the necessary investments for the renewal and magnifying of the siderurgical park. This lack of investments provoked, also, the loss of competitiveness of the Brazilian siderurgical companies front to its competitors in the international market. The exit of the State of the siderurgical sector, from the privatizations effected in the beginning of the decade of 90, brought new perspectives for the sector. However, the ticket of the main siderurgical companies for the private initiative opened spaces for the entrance of new companies in the sector, incited the rivalry enters the established companies already in the industry and modified the relative power of negotiation between the siderurgical companies, its suppliers and its purchasers. The threat of substitute products, although pparently low, continues to go up to around the industry, being hindered it to repass increases in the costs and to increase its prices freely. The alteration in the control of the companies, associated to the Changes in the competitive environment, has provoked a bigger diffusion of the concept and the importance of the strategy between the siderurgical companies. These companies, who before were not worried about the strategy or they did not present consistency in the chosen strategies, now demonstrate significant reductions in its costs and show standards of differentiation or choice of market niches where to act. It is important to stand out that these new strategical choices also are influenced by the relation that some of the companies possess with its matrices and the governments Brazilian, of the countries of its matrices and the countries where they possess commercial interests, as Argentina, Chile and United States. The studies of Porter (1980, 1985) had been the base for the Characterization of the competitive environment and the identification of the boarded competitive strategies in this work. The competitive environment was detailed using the model of the five forces of Porter: threat of new incoming, threat of substitute products, to be able of negotiation of the suppliers, power of negotiation of the purchasers and rivalry enters the established companies already in the industry. The classification of the competitive strategies of the companies, in turn, had as base the tipologia of generic strategies of Porter, with its definition of strategies of leadership in total cost, differentiation and approach. Referencial theoretical of this work also presents tipologias alternative to the one of Porter, as proposal for Mintzberg (1988) and Resource-Based View, that it is a chain that focuses the company of the point of view of the insumos and goes against diverse ideas of Porter, however still needs validation by means of empirical research. The tipologia of Porter if showed adequate to the classification of the strategies of the Brazilian siderurgical companies, however still it is an incognito if the additional Explanatory power that could be proportionate for the tipologia of Mintzberg would compensate its lesser level of parsimony in relation to the tipologia of Porter.