It is now well recognized that all types of regulation are imposing costs on our society. The studies which have tried to evaluate these costs are numerous and their methologies are diversified. This paper is proposing a critical analysis of these methodologies and of the results obtained by researchers who have tried to evaluate the costs of regulation. Before that, however, we develop an analytical framework for examining the impact of regulation on firms'costs, economic efficiency and the well-being of the population in general. This section will be based on cost-benefit analysis