Financial segment is the core division to decide the country's gross domestic product ( GDP). The considerable and constant development of any country is based on the financial strength of the country. Last few decades observered the increase of financial reforms, liberalization and globalization of Indian financial system coupled with rapid revolution in information technology (IT).The paper presents the advantages of applying data warehousing and data mining (DWDM) techniques in customer relationship management (CRM) of the financial divisions like banking. It is a procedure of analyzing the data from various perceptions and summarizing it into precious information. Data mining ( DM) aids the banks to look for unknown pattern in a group and determine unknown relationship in the data. These methods facilitate useful data analysis for the banking division to avoid customer harassment. And also fraud is an important problem in banking domain. Identifying and preventing fraud is hard, because fraudsters develop new techniques all the time, and the techniques grow more and more difficult to avoid easy finding.