Abstract: Objective: applied vibration stimulation of different frequencies to volleyball athletes in a 9-week strength training and analyzed which frequency is better in improving athletes' strength and balance ability. Methods: randomly divided subjects into control group, 30 Hz group and 45 Hz group, tested pedaling and stretching peak force through 3 dimensional dynamometer before and after the experiment, and tested balance ability through balance tester. Result: The peak force of experiment group was better than that of control group, the test data of 45 Hz group was significantly better than that of 30 Hz group; in terms of relative impulse, there was no significant difference in running take-off between 30 Hz group and control group, all the indicators in experiment group were significantly different as compared with control group and the test data of 45 Hz group were better than 30 Hz group; in balance ability test, the difference between experiment group and control group was dramatic, 45 Hz group was better than 30 Hz group except left lower limb's balance ability in X-axis direction. Conclusion: The vibration stimulation has positive effect on athletes' strength and balance ability, 45 Hz vibration stimulation is better than 30 Hz vibration stimulation in improving athletes' strength and balance ability.

Key words: different frequencies, vibration stimulation, volleyball, lower limb strength, balance ability