Topic of my master thesis under the name „Hobbes's and Rousseau's understanding of human nature in contractualistic concept of the state“ is to analyse and critically discuss Hobbes's and Rousseau's state theories with support on two different disciplines in philosophy: philosophical anthropology and philosophy of politics. Both disciplines are closely connected in philosophical works and conceptions of Thomas Hobbes and Jean Jacques Rousseau. One of the important connections between those two disciplines within philosophy is concept of social contract. Concept of theory of social contract is basically consisted of three components: natural state, contract itself and the effect of that contract, which is the state. Philosophical anthropology is weaved in foundation of understanding of natural state which ultimately, although from different reasons, brings individual to conclusion of the social contract. The method and conditions under which social contract is concluded in an essenatial sense defines the shape of political arragement, which I will endeavor to show through comparison of two different philosophies of politics. For that purpose I will, firstly, try to signify historical-social, and also philosphical frame in which these two philosophers acted. After that I will, by Hobbes's method, try to disassemble their political theory to natural state, social contract and the state. I will point out their similarities and differences, and then I'll have them connected again in conclusion to establish the connection between their understaning of human nature and constituting the most appropriate form of the state.