This diploma thesis provides an overview of the aspects connected with financial assurance of liability for environmental damage. First parts of the work define the frame for this topic through its essentials terms and theoretical basis. Also there are introduced the main functions of economic instruments. Part 3 briefly focuses on the ways of codification of liability in the international public law. The main part of this work is dedicated to an adoption of the polluter pays principle to the European Union law and the Czech national law system. Thus parts 4 and 5 describe and evaluate efficiency of this liability system from the perspective of obligation to assure a financial security. Last part gives a list of possible instruments which may be used as a suitable financial security according to the statute n. 167/2008 Sb.