Particular ways of interpretation of law applied by the European Court of Justice (hereinafter referred to as 'ECJ'). Role of the ECJ in filling of the 'gaps' of European law. Judgments of the ECJ and its position and significance in the process of formation of law. Basic principles formed by the ECJ. (Un)binding judgments of the ECJ. Role of the preliminary questions and opinions of the ECJ in formation of law. Analysis of Lugano Opinion. Conclusion dealing with the significance of judgments, preliminary questions and opinions of ECJ in the process of formation of European law. Question of acceptable bounds of extensive interpretation and jurisdiction of ECJ.