A seat test body is provided for vibration measurements. In order to be able to obtain, during vibration measurements in the whole spectral range, measuring results which can be compared at least qualitatively with corresponding test person measurements, the buttocks imitation and the back imitation of the seat test body are each formed by padded hard parts. The hard parts of the buttocks imitation and those of the back imitation imitate true to life the corresponding bone structure of a human skeleton at least with respect to the portion of the skeleton which is loaded during sitting. With respect to the layer thickness, the softness, the elasticity and the damping behavior as well as the local distribution of these parameters, the padding of the hard parts anthropomorphically imitates the soft parts in the buttocks area and the back area. For achieving the required sitting weight of the seat test body, a passive ballast in the form of several weights is placed on the interior side into the buttocks imitation and/or is placed on shelf-type consoles on the interior side of the back imitation. Relative to the buttocks imitation, the back imitation is disposed to be swivellable within a limited angular space about the hip joint point and is elastically prestressed in the sense of a stretched position of the back part and the buttocks part.