This study explores the relationship between antecedent factors and users' acceptance of Knowledge Management Systems through extension of Technology Acceptance Model, based on the survey data from two hundred and thirty-two respondents. In order to extend the previous model, new constructs such as feeling and perceived value were added to the research model. Overall, four dependent variables-perceived usefulness, perceived ease of use, perceived value, and intention to use the system-were investigated in their relationships with antecedent variables. The results of the analysis indicated the significance of the new constructs introduced in this research. Implications of the study and suggestions for future researches were discussed.