Tacit knowledge is the source of knowledge creation, but the organization and retrieval of tacit knowledge using IT has not been discussed much. In this paper, we defined Internal Knowledge Evolution Network (IKEN) to describe the knowledge evolution process from tacit to explicit, and applied the Case-Based Reasoning (CBR) integrating with Direct-Case-Linkage technique to support the IKEN management. To argue that the technique can better support the retrieval of tacit knowledge, we first implemented a prototype system, and then evaluated the system by carrying out aperformance test.