The foremost goal in writing this report is to develop a brief description about a topic that blends basic concept about an Accounting Information system of Mercantile Bank Limited. This internship report is one of the most widespread reports. In this tie I have selected the area i.e. Uses & Application of Accounting Information Systems (AIS) in Mercantile Bank Limited. Department of Bachelor of Business Administration (BBA), Metropolitan University, Sylhet has espoused the policy of assigning an internship report to every student as a part and parcel of the academic curriculum of the BBA program. In these topics I have presented assorted part of Mercantile Bank Limited which uses accounting information system.