PURPOSE: The purpose of this study was to investigate the comparison of balance on Stable Ankle(SA), Instability Ankle(IA) using Cumberland Ankle Instability Tool(CAIT). METHODS: Total 54(SA: 27, IA: 27) subjects were volunteered to participate in the study. SA can be defined CAIT score ${geq}28$, with no history of injury to ankle. IA can be defined persisting symptoms of giving way and ${leq}24$ on the CAIT after ankle sprain. the balance measured using Biodex Balance System$^{(R)}$(BBS). BBS instability protocols used static, dynamic balance level less stable(2), moderate stable(4) and level more stable(8). RESULTS: There were significant differences at overall, Anterior-Posterior(AP), Medial-Lateral(ML) of static balance, dynamic balance level 2, 4. The dynamic balance level 8 found significant difference at ML, but not found significant differences at overall, AP. CONCLUSION: We suggest that CAIT is acquired more exact information for IA intervention, as balance measured.