| With the rapid development of Internet technology, the traditional telecommunications industry has been far-reaching impacted by the Internet. As the tremendous impact on the traditional fixed-line voice services by mobile voice services, China's two fixed-line network operators—China Telecom and China Netcom have been emerged into a larger decline of the voice business in 2007 except the number of users and income of broadband service maintained a highly increasing. Broadband Service has become a competition focus of the two fixed-line operators. Intense competition in the market for broadband customers resulted in an unstable state; the operators are facing to a serious loss of customers. How to prevent the loss of customers and keep the customers becomes one of the focuses for Operators attention.This paper, on the basis of the analysis on China's telecommunications enterprises of the new competition pattern, points out that the status quo telecommunications enterprise CRM and the problems existing in customer loss management, the theoretical framework of CRM and the core of analytical CRM that elaborated the importance of data mining in the analysis of the loss of customers. This paper have shown the competition in Chongqing broadband services market and had a comparative analysis of the advantages and disadvantages between Chongqing Telecom and Netcom broadband business, and also analyzed the status quo and the impact of the customers' churn of Chongqing Netcom broadband business. In order to support the Market Expansion and the Market Maintenance by information means. Chongqing Netcom constructed the Business Analysis System. This paper describes the system structure and the data organization and the main contents of Chongqing Netcom decision support system, and does a detailed analysis of Customer Churn Alarm in Business Analysis System. Finally, though the potential of customers' Churn that analyzed by Customer Churn Alarm, we design a different marketing strategy and service strategy in order to preserve the customers. |