To strengthen the foundation for national information development, Taiwan government has persistently implemented information education at different levels of school. This research is a three-year project on "Research on the Development of Information Aptitude Scale," sponsored by National Science Council of Taiwan. It was designed primarily to develop an information aptitude scale appropriate for application in junior high and vocational high schools in Taiwan so as to help students understand whether they are equipped with the ability to enroll in information-related departments and to pursue a career in information. This article separately describes the three stages of developing the scale for vocational high schools. During the first year test questions for the information aptitude scale were written, and the reliability and validity of scale test questions were analyzed during the second year. Now the third-year sub-project is being conducted, focusing on establishing norms and interpreting test results of the scale.