It is widespread that banks always had a principal role in all contemporary financial systems. The fundamental role of them, typically, is the transformation of liquid deposit liabilities into illiquid assets such as loans; this makes banks inherently vulnerable to liquidity risk. Due to the potential risks in global financial environment, it has to be assured that a financial institution, such as a bank, is able to continue to perform its fundamental role. Liquidity represents the capacity of a bank to fund increases in assets and meet obligations as they come due, without incurring unacceptable losses (Basel Committee, 2008a). In other words, we could define that liquidity is assuring access to cash when it is need. Bank’s liquidity si about the confidence of counterparties and depositors in the institution and its perceived solvency or capital adequacy.