The purpose of this study is to explore the correlations among knowledge Management strategy, school-based management and school effectiveness. It includes; (a) to investigate the present status of knowledge management strategy, school-based management effectiveness; (b) to compare the differences among the knowledge management strategy, school-based management, school effectiveness; (c) to probe into the correlation between knowledge management strategy and school-based management, knowledge management strategy and school effectiveness, school-based management and school effectiveness. Some of 44 public elementary schools in Tainan are selected as samples. One way ANOVA, Canonical Correlation, Multiple Regression, Cluster analysis, Discriminant analysis and T-test are applied on the data obtained from questionnaires of the 44 schools. The results show that those schools adopted codificational knowledge management strategy have positive influence on both school-based management ability and school effectiveness. Those schools adopted codificational knowledge management strategy are shown to be better on both school-based management ability and school effectiveness.