The purpose of this study is to apprehend a problem of user affordance and to suggest an improvement plan to make the better usability of Diagnosis-Supplement System for basic academic skill. Starting in 2013, from 5 cities and provinces, this system was developed, and in 2015, it was completed construction in all (17) provinces. Now, this system serves diagnosis test and supplement study materials for underachievement students from 3rd grade to 8th grade. As of 2015, the role of this system is gradually increased that 16 million students, about 4% of pupils throughout the country are now using it. In turn, this study tries to analyze various ranging requirements of teachers and experts by doing focus group interview in terms of user affordance and try to suggest the way to improve this system for the sustainable use. Henceforth the results of this study, which includes specific problems of physical, cognitive, sensual affordance and a design prototype to improve these problems, can be an important base material for the process of improving Diagnosis Supplement System for Basic Academic Skill with effective and intuitive system.