Objectives: The purpose of this study was to suggest a more effective exercise method for chronic ankle instability by comparing an effect of strengthening exercise and the balance exercise. Methods: After recruiting 24 people in their 20s with chronic ankle instability(CAI) and dividing them into two groups. The control group performed strengthening exercises(calf raise, heel walks and theraband exercise) three times a week for four weeks for 30 minutes. In the experimental group, they conducted a combination of ankle strengthening exercises and balance exercises(dumbbell cross exercise, BOSU Exercise) three times a week for four week s for 40 minutes. We measured ankle instability index, muscle strength, and balancing abilities before and after the training. Results: In both the experimental group and the control group, there was a significant difference in the Cumberland ankle instability tool(CAIT), static balance before and after the intervention(p< .05). But there was no significant difference between the two groups(p >.05). In the dynamic balance, the experimental group had significant differences (p< .05). However, the control group had no significant difference(p >.05). There was no statistically significant difference in the outcomes both the experimental group and control group(p>.05). Conclusions: We propose that ankle strengthening exercises and balance exercises can be an effective clinical exercise method to improve the ankle instability and balance ability of people with ankle chronic ankle instability.