During the 2016 Kumamoto earthquake sequence, Tsujun Bridge in Yamato Town, Kamimashiki County, Japan, suffered significant failure including a water leakage from stone canals. In this study, in order to evaluate ground motions at the failure site, microtremor measurements and temporary aftershock observation were conducted at the site. The evaluated site amplification and phase effects between the damage site and K-NET Yabe (KMM009) site are very similar. It indicates that the observed ground motions at K-NET Yabe site during the 2016 foreshock and the 2016 main shock can be regarded as the ground motions at the failure site.