The purpose of this study was to evaluate the changes of pre-motion time (PMT), pre-motion silent period (PMSP), and switching silent period (SSP) before and after the training using balance-mat. Twenty healthy people aged 21-36 years old (average 26.5 years old) were subjected to a series of experiment. These were randomly divided into two groups (10 subjects each), control and balance-mat group. Activities of M. Soleus and M. Tibialis anterior were recorded by electromyogram (EMG) for the duration subjects were tried to raise their both heels as quick respond to a flashing lamp. Intervention consisted of 3minutes standing on the floor in control group, and 3 minutes standing on the balance-mat in balance-mat group. Then EMG was recorded as the same manner after the intervention in each group. There was no statistical difference of duration of PMSP and SSP between the two groups before intervention. On the other hand, those in balance-mat group were significantly shorter than those in control group after intervention. In addition, in balance-mat group, duration of PMSP and SSP after intervention were significantly shorter than that before intervention. There was no statistical difference of PMT between before and after the intervention. These results suggested balance-mat training was effective for shorten the duration of SSP and PMSP, that lead to control the posture function.