This study was conducted to develop a "High School Credit System Course Selection Practice Program" to assist high school freshmen and third-year middle school students in career planning and understanding the high school credit system. The program consists of "School Designated Course Settings," "Student Selected Course Settings," and "Student Selection Sheets," and is designed using Excel's data validation and macro functions to facilitate course offering and designation. Additionally, a career education program for third-year middle school students was developed for use in subjects such as "Technology and Home Economics," "Careers and Occupations," and creative experiential activities. It is recommended to modify this program according to the guidelines of local education offices, and subsequent research analyzing changes in students' career maturity and high school admission decision factors after applying the career education program is expected to further enhance the validity of the study.