PURPOSE: The purpose of this study was to investigate the difference of trunk muscles activity during abdominal hollowing and bracing contraction in various position. METHODS: This pilot test was carried out in a volunteer sample of normal adults(n=24) without a history of low back pain or injury. 24 subjects were randomly allocated to three groups(n=8) as a contraction method respectively. In hooklying position, trunk muscles activity of subjects was measured using EMG in various bridging position. RESULTS: Abdominal bracing contraction made to more great trunk deep and superficial muscles activity than hollowing contraction.(p<0.00) Especially, Multifidus activity was the biggest.(p<0.00) CONCLUSION: The result from this study showed that abdominal bracing contraction made to more balancing activity of trunk muscles than abdominal hollowing contraction. Thus, It will good for trunk muscles unbalanced LBP patient to improve lumbar stabilization.