The author describes the state's fulfillment of the fiscal mechanism which is capable to provide sufficient financial coverage of the state and local budgets; facilitate the achievement of strategic priorities of steady development in the state and regions through rational and substantiated usage of material, social and natural resources. The role of tax elements within the fiscal mechanism in providing the ecological, economic and social imperative of social development in Ukraine is evaluated.The structure of the fiscal mechanism is offered. The author shows that the key elements of it include the mechanism of revenue mobilization, distribution and usage of budget income, maintenance of the intergovernmental budget balance and public debt management. The author emphasizes that in the mechanism of income mobilization, besides the mechanism for mobilizing intergovernmental and official transfers and the non-tax mechanism, a dominant role plays the tax mechanism of income mobilization.The author claims that at present there are significant reserves for improving the efficiency of the tax elements in the fiscal mechanism. The author proves that it is expedient to increase the environmental role of ecological taxes because despite the significant rise of ecological tax receipts, their amount is still lower than the level of financing of capital and current expenses which are aimed to protect and restore the natural environment.The author demonstrates the need to ensure a fair redistribution of income which is based on the growth of the social role of income taxation and establishment of high social standards for the estimation of labor force cost. The author states that its level in Ukraine is rather low if to compare its average index in the countries of the European Union. The author denotes that there is an urgent need to expand the range of tax privileges and preferences for activating entrepreneurial activity in the state, with increasing of the fiscal control over the effectiveness of their use.