The main goal of my thesis was to present a compact view on current adjustment of the taxation of income of natural persons resulting from business and other forms of self- employment with the emphasis on the description of tax records, lump-sump expenses and lump-sump tax. I tried to apply articular structural elements of the taxation of income of natural persons resulting from business and other forms of self-employment and to present its interpretation. Regarding the complexity of the act I consider to be useful to present some practical examples which would enable better understanding of the institutes described and I also tried not to forget the judgments relating the interpretation. Lump-sump tax which I tried to analyzed, is not very spread in the Czech Republic even though it should contribute to simplification of the setting of the Income Tax for tax-payers running their business on a mall scale. The reason for this state is, in my opinion, the impossibility to apply tax refund, impossibility to apply tax loss and one of the reason can also be uncertainty of economic result because if tax-payers reach lower income and higher expenses than those ones which were counted while setting lump-sum tax, their tax liability doesn't change. In connection with the change of the Act of Accounting, on the 1st...