This study aimed to develop an instrument to measure the effect of Taiwan’s policy on global education. Four constructs were developed, namely rights and responsibilities of global citizenship, competencies of global citizenship, participation of global citizenship, and reflection of global citizenship. The instrument was tested with a sample of 1,112 elementary school students in Taiwan. Content validity was established. Exploratory factor analysis and confirmatory factor analysis confirmed construct validity. All the indexes were satisfied except the convergent validity.