PURPOSE: The purpose of this research was comparing and analyzing the exercise effect for the public who was not suffering back pain exercise in improving the waist flexibility, the waist muscular strength and the waist sense of equilibrium after grafted in William & McKenzie exercise with swiss ball. METHODS: 16 people who were not in progress of the chronic low-back pain were recruited. They were grouped into 8 for each experiment(GSBE=Group which play swiss ball exercise, GWME=Group which William & McKenzie exercise). RESULTS: The following result was obtained through measurement of three items in both pre and post examination. CONCLUSION: Comparing the average result of flexibility improvements of each group after 12-week exercise program, the result showed that GSBE was more effective than GWME with increase of muscular strength. Comparing the average result of muscular strength of each group after 12-week exercise program, the result showed that GSBE was more effective than GWME with increase of flexibility improvements. Comparing the average result of sense equilibrium of each group after 12-week exercise program, the result showed that GSBE was more effective than GWME with increase of sense equilibrium.