The part of the inhabitant near the railway viaduct made a complaint about the ground vibration. Therefore, the vibration measurement was carried out installing the seismographs on the ground surface and on the viaduct. It was found that the cause of the complaint was the beat phenomenon observed in the ground vibration. By comparing the 3-dimentional eigenvalue analysis with the measurement, and by comparing the inverse analysis of the train force with the measurement, we investigated the cause of the beat phenomenon. The amplification of the ground vibration was also examined.