The purpose of this study was to explore the effect of game-based exercise on physical function, exercise self-efficacy and exercise enjoyment of the pre-frail elderly. A total of 20 pre-frail elders were recruited from two community care centers in Miaoli City, and randomly assigned them into game-based exercise group or aerobic exercise group. The game-based exercise program, which integrated game elements into aerobic exercise, muscle strengthening, and balance training were designed to emphasize fun, sociability and low competition. Aerobic exercise program was a continuous and rhythmic exercise of the limbs in accordance with the music rhythm. Both groups completed the assessments of physical functions, including 10-m walk test, 5 times sit to stand test, tandem stand test, and functional reach test before and after the training. The questionnaires of exercise self-efficacy and exercise enjoyment were completed after 12-week training. The Mann-Whitney U test was used to examine the group differences. Results showed that the game-based exercise group had a significant improvement. The aerobic exercise group showed tendency in improvement, although they did not reach statistically significant differences. However, there was a significant difference between the groups in the pre-post change of functional reach test. In addition, the exercise self-efficacy and exercise enjoyment scores of the game-based exercise group were significantly higher than that of the aerobic exercise group. Based these findings, we concludes that the game-based exercise training can promote physical function of the elderly in the early stage of frailty. Furthermore, game-based exercise training influenced the exercise self-efficacy and exercise enjoyment of elderly, and enhanced their motivation for exercise.