As service firms continue to seek unique sources of sustainable competitive advantage, service quality has been discussed as a potential alternative to traditional skills and sources. The information of customers is generally believed to be a key component in creating corporate responsiveness to customer requests. In order to develop and maintain long-term close relationships with customers(CRM), service firms need to build an effective and ongoing service quality information system(SQIS). Service firms that formally collect customer-related information and internal service quality information were to be more responsive. The purpose of the present study is twofold. 1. How to nicely get the information on the service quality. 2. How to build a SQIS. One of numerous examples from financial service-sector firms is given to show that SQIS can be developed to improve service quality. This paper investigates SQIS of a Korean commercial bank as an example. Implications and strategies for building an effective SQIS for financial service-sector firms are discussed, and directions for future research are indicated.