The purpose of this study is to compare the motion of center of mass movement at crossing obstacles. Ten young persons tested with four conditions. Center of mass and center of pressure inclination angle (COP-COM IA), angular velocity (AV), angular velocity (AV), toe-obstacle clearance (TOC), joint angle (JA) of swing limb, and electromyography (EMG) of gluteus medius, gastrocnemius, and tibialis anterior at leading and trailing limb passing over the obstacle were assessed. When leading limb was passing above the obstacle, IA significantly decreased．In case of trailing limb, IA significantly increased and AV decreased．Joint angle and TOC significantly increased as the obstacle became higher．EMG of stance limb did not change. At the higher obstacle, the anterior motion of COM decreased at leading limb. On the other hand, it increased at trailing limb．From these results, it was suggested that different strategy between leading and trailing limbs existed.