The purpose of this article is to add an opinion to the variable concepts of the public nature of commercial bank and to suggest its legislation into the banking act. Generally the concept of public nature is known as the public welfare although its contents are very vague and various. Commercial banks are originally and practically profit making corporation taking serious views of share holders interests. But the public nature of banks should be considered in maintaining its credibility, securing the protection of depositors, and facilitating smooth functioning of financial services, to ensure sound and appropriate operations of the business of banks, thereby contributing to the sound development of the national economy. The public Nature of the commercial banks and its autonomy to act business freely without restriction are not necessarily contradictory or conflicting. Writer of this article tries to tell the public nature in banking business from that of bank institution, because the institutional public nature can not be ignored while their business operations have a public nature in exercising their financial functions. The writer thinks the public nature of bank is the cost of its licence which allows to act banking business freely and without certain restriction targeting general public, there by creating credits. The writer also suggests the legislation of public nature of bank into the banking act so as to confirm the social responsibilities to consider the public welfare.