One of the most recent problems of many procedures in EU-legislation is the scope of application of Art. 290 and 291 TFEU. This research investigates the practical application of Art. 290 and 291 TFEU with many useful examples and finally proposes a delineation that leads to a coherent system of EU-legislation. Furthermore, the author addresses various connected problems, such as the requirements that a basic act which delegates the power to enact delegated acts and implementing acts has to meet. In particular the author also explains todays role of comitology committees, Commission expert groups and EU-agencies within the preparation and the controle of delegated legislation.