Web-based course management systems have been overwhelmingly accepted by instructors, students, and educational institutions. In order to improve quality of existing systems, the questions must be answered are what underlying dimensions of user’s satisfaction exist and on which of those dimensions we should apply the resources. In this study, the principal component analysis was undertaken to determine the underlying dimensions. Then the scores for each dimension were calculated, and bivariate correlations between the dimensions and the user’s satisfaction were used to assess the marginal importance of each dimension in improving web course management systems. In addition, the survey instrument was tested for reliability and validity.