The main purpose of the study is to conduct a comparative analysis of the terms “budget federalism” and “tax federalism” based on the research results of scientific works of modern Russian scientists, as well as identifying the relationship between these concepts. The methodological basis for the job is a com-bination of dialectical, positive, structural (systemic), normative methodological approaches. The article summarizes the conceptual approaches of modern scientists to the interpretation of of these terms, comparative characteristics of these concepts in the light of their qualifying features. In addition, we conducted a fairly comprehensive comparative analysis of the implementation of the principles of budgetary and fiscal federalism, based on identified correlations reflected a functional relationship diagram elements category of “budget federalism”. Based on the analysis the conclusion about belonging of the concept of “tax federalism” to the structural elements of the “budget federalism” and the need to implement the principles of federalism in the process of forming the country's fiscal policy.