Recently, the riding comfort of passenger cars has become important, as well as driving performance and control stability. To improve riding comfort performance, it is necessary to evaluate comfort quantitatively and take discomfort-decreasing measures. In this study, using acceleration magnitude, frequency (below 3 Hz), phase difference, and acceleration amplitude ratio as the input parameters, the characteristics of vibratory sensibility were surveyed with driving posture in a shaking experiment to identify the parameters that affect sensation. A vibration experiment was conducted using the standing wave of two axes, X (fore and aft)-Z (vertical) and Y (lateral)-Z (vertical). As a result, the riding sensation tends to depend on the frequency and the amplitude ratio. Next, the human body response was measured using an input condition in which the difference of sensation appeared notably in the experimental results of grasping the sensibility characteristics. Measurement points were the pre-head, occipital, chest, pelvis, and ischium. Moreover, we analyzed human vibration responses by observing the relative movements of body parts from the side-view and rear-view. We verified the correlation between these responses and sensations. As a result, this study shows that riding comfort can be improved by decreasing lateral vibration at the chest and pelvis.