To improve quality of an product We have adopted new approaches such as SPC(Statistical Process Control), CIM(compure Integreated Munufactture), QDF(Quality Development Function), etc. In spite of using these approaches, an organization should fail to achive its true goal if that organization didn't developed its cooperative quality culture which is the total of collective and shared learning of quality-related values as the organization have developed its capacity to survive in its external environment and to manage its own internal affairs. In this paper, I analyzed the current quality culture of Korea Telecom and tried to suggest how Korea Telecom develop its service quality based on the quality culture.