The educational porductivity mobility of Korean, English, Mathematics during middle school years was analyzed using Korean Education Longitudinal Study(KELS) data. The results show that Mathematics had the highest and English had the lowest mobility, and male students had higher mobility than female students. Mobility between the first and the second year was higher than between the second and the third year in Korean, and between the second and the third year was higher than between the first and the second year in English and Mathematics. The lowest grade(grade 5) had higher mobility than the highest grade(grade 1), English had the lower mobility then Korean and Mathematics for highest grade students, and Mathematics had the highest mobility for lowest grade students. Male students had lower mobility in both the highest and the lowest grade. The implications of the results were discussed.