This study probes into the definitions, structures and functions of existing knowledge management systems (KMS) in Taiwan by literature review to reveal the current development of KMSs in the area. The study finds that the basic functions of KMSs remain as knowledge acquisition, document management, search, and community forum. However, these systems are insufficient of core competency process, such as construction of expert system and case analysis. The findings provide valuable reference for selection of KMSs, so as helpful in research and development of KMSs.