Floor vibration is an important factor in living conditions. Recently cases to need countermeasures for floor vibration reduction increase because building life becomes long, and the criteria of vibration may sift by replacement of residents or the exposure force may be large by change of neighboring traffic. In this research, influences that prior experience of floor vibration gives for the judgments of allowance for reduced vibrations was examined in sensory evaluation test. By the examination, it was shown that reduced vibrations may be allowed by being reduced at fixed ratio, no matter the vibrations are larger than individual absolute acceptable limit of examinees. And the unevenness of reduction ratio for allowance caused by individual difference is smaller than the unevenness of the absolute acceptable limit of examinees.
