The author has undertaken to analyse one of the most significant legal problems – the problem of principles of proper legislation He has given attention to the fact that there is a distinction between the principles of creating the law and the principles of indicating the method of creating the legal act. Though in democratic state, parliament plays the special role, nevertheless its power must be limited. During the legislative procedure, the parliament is obliged by principles of proper legislation, such as vacatio legis, non retroactive of the law, protection of just vested interests or prohibition of introducing any changes in the taxation system during the taxation year.