Recently, a great deal of corporations have adopted knowledge management system with eagerness to enhance the company competitiveness. However, since the main feature of knowledge management system is not just a simple information system but another entity creating intangible assets tailed "knowledge", we need to develop a new approach to investigating the performance and acceptance of knowledge management systems from a perspective allowing knowledge-sensitive constructs. In this regard, we develop new constructs like knowledge schema and several knowledge circulation-related activities. As a research model, we adopt a famous technology acceptance model or TAM by Davis (1989), and extend it into incorporating knowledge schema. With the statistically valid and usable questionnaire survey data collected from 886 respondents in a big corporation typically using knowledge management system, we induced a robust result empirically, saying that knowledge schema and knowledge circulation activities are valid determinants of performance and acceptance of knowledge management systems.