In recent decades, financial stability as an economic system object is taken into consideration in the policy making more than ever before. The Central banks and most financial institutions, including IMF, World Bank and Bank of International Settlements, have published numerous reports about financial stability and the considerable part of their research activities addresses to study in this field. A simple definition, financial stability is a state that the system is not in a critical condition. Various factors affect to financial stability that among them macroeconomic variables (inflation, GDP, exchange rate) and banks’ special conditions (the profitability of banks, the ratio of cost to the income ratio of loans to assets of banks) are the most important. The financial stability has a positive effect on financial institutions and banks' performance and can improve the efficiency of their activities. This paper aims to compute the financial stability indexes in Iranian banks and compare their calculated indexes among them. The results show that the financial stability of the selected banks is different and financial stability indexes in the private and public banks are different.