With this paper, he will explain in more detail what the budget is and budget law, how the budget is adopted and what is financed from it, and which laws and principles must be followed when adopting the budget. The budget is essentially all the expenditures and revenues of a state from which public and state needs are financed, and every year a budget plan is made for the future period of one or more years. Budgetary law is a branch of financial law that makes up a set of norms related to the preparation, approval and application of the state budget. The new Budget Act in the Republic of Croatia entered into force on January 1, 2022, and it includes the Directive of the Council of the European Union 2011/85/EU of November 8, 2011 on requirements for budget frameworks of member states. When adopting the budget, care must be taken to apply the principle of accuracy and unity of the budget, the principle of the budget year, and other principles. Budgetary law in the legal sense is a legal act by which the representative body determines expenditures and revenues for the functioning of the state during one fiscal year.