Abstract: The technology acceptance model (TAM) has been applied in various fields to study a wide range of information technologies. Although TAM has been developed in this research stream in Taiwan, TAM's issues of measurement have received scant attention. A robust model must perform measurement invariance across different respondent subgroups to ensure that various sample profiles have the same relationship. A survey of regarding E-portfolio system reuse intention was constructed, resulting in 360 valid responses across subgroups differing in gender, grade, and levels of willingness to share, to examine the measurement invariance of TAM. The results empirically support the validity of our TAM instrument for evaluating E-portfolio reuse intentions behavior. These findings suggest that men and women, differing grades, levels of willingness to share conceptualize the TAM construct in similarly. The implications of these results enable us to understand TAM's validity in E-portfolio acceptance research.