The article investigates the importance of macroeconomic statistics systems as a methodological and information base for the studying of financial sector. The System of National Accounts (SNA) is a coordinating framework for all systems of macroeconomic statistics. Monetary and Financial Statistics can be seen as an extention of the SNA regarding financial sector activities. The System of National Accounts and Monetary and Financial Statistics are consistent and harmonized. That is why the same conceptual and methodological approaches to the analysis of financial sector development can be used. The information base of national accounting allows to investigate the role of financial corporations as providers of financial services, namely their participation in the process of social reproduction. The analysis can be deepened by identifying nine subsectors within the financial sector (Central Bank, deposit-taking corporations except the Central Bank, money market funds (MMF), non-MMF investment funds, other financial intermediaries except insurance corporations and pension funds, financial auxiliaries, captive financial institutions and money lenders, insurance corporations, pension funds). The rationale for subsectoring is nature of financial activiies of institutional units belonging to the financial corporations' sector. In addition, subsectors can be combined into different segments depending on the objectives of the study: System of National Accounts divides financial corporations into three categories: financial intermediaries, financial auxiliaries and other financial corporations. Monetary and Financial Statistics applies a different approach for the financial corporations' subsectoring. All subsectors are grouped into two segments: money-issuing (Central Bank and other depository corporations – deposit-taking corporations except the Central Bank and money market funds) and money-holding (the rest of subsectors). The combination of methodological and informational potential of the System of National Accounts and Monetary and Financial Statistics provides a comprehensive analysis of the functioning of the financial sector by highlighting various aspects of the financial corporations' activities.