transient vibrations caused by a sudden change in the road surface under steady-state random vibration subject the human body to unpleasant sensations. However, it is very difficult to examine each part of the seat structure and physical properties because the measurement position of acceleration sensors with the conventional evaluation method are limited to the hipbone on the seat cushion and lumbar on the seat back.In this paper, in order to evaluate three kinds of driver seats having different structures and physical properties, we dynamically measured body pressure distribution, which are mainly made with static measurements, on a pavement inducing transient vibrations. We analyzed each part of measurement data by means of a new human engineering index, which is body pressure change rate over time. We next investigated the correlation between the analyzed data and the subjective evaluation, and found the mechanism causing unpleasant sensations during transient vibrations. The results of our successful research allow making improvements in each part of the seat structure and physical properties.