It is becoming more vital than ever before for business to manage customer relationship and build customer loyalty. Information systems and data mining techniques have significant contributions in the customer relationship management process. In the dynamic business environment, information systems need to evolve to adapt to the change in requirements, which is driven by customer relationship management. An evolving information system is proposed in this paper and discussed by focusing on a specific type of knowledge, namely association rule. With new classes and attributes created based on new knowledge and user requirements, the evolving information system is capable of collecting, processing and providing more valuable information on customers, to support customer relationship management.