There were 13 standard spans of variant span length and pier height tested at early stage of Taiwan High Speed Railway's operation. The test was aimed to verify the actual dynamic responses meeting the design code, and to establish the initial values of bridge structure dynamic behaviors. In this test, triaxial accelerometers and triaxial velocimeters were mounted on box girder to measure the structure vibration of prior, during and after train passing, which refers to ambient vibration, force vibration and free vibration, respectively. More than one hundred train passing events have been recorded. The measurements were utilized to extract the distribution of natural frequency, dynamic response comparing to different train speeds and different span lengths.