ABSTRACT The main purpose of this study is to investigate the usage of web-based teachers' training in elementary and high school. This study adopts motivational orientations and TAM to explore the related factors that affect the usage of web-based teachers' training. The study depends on literature analysis and uses the questionnaire to collect data. A total of 658 subjects attending teachers' training courses are from K12 Digital School. The collected data is processed and analyzed with SPSS for Windows 10.0, and statistical methods adopted in this study are descriptive statistics, t-test, one-way ANOVA, regression analysis and so on. The main findings show that there are 8 motivational orientations for web-based teachers' training and motivational orientations are significant differences among subjects in different age, status, school level and teaching years. Furthermore, computer self-efficacy, social relationships and attitude toward using will significantly affect the usage of web-based teachers' training positively, and perceived usefulness and perceived ease of use toward web-based training system will significantly affect attitude. As for perceived ease of use toward web-based training system, it will significantly affect perceived usefulness toward web-based training system and be affected by computer self-efficacy positively. Finally, based on the research findings, this study proposes conclusions and suggestions for the related organizations and the follow-up research.