Previous studies have reported the effect of removing the nucleus on biomechanical responses of the human spine to static loadings. However, few studies have dealt with the whole-body vibration condition. The purpose of this study was to investigate the effect of a single-level (L4-L5) nucleus removal on vibration characteristics of the whole lumbar spine in the presence of a physiologic compressive preload, and also to evaluate the preload effect on the vibration characteristics. A 3-D non-linear finite element model of the lumbar spine (L1 to sacrum) subjected to the physiologic conditions of a compressive follower preload was developed and validated. Comparative studies on forced vibration responses between the intact and denucleated models were conducted. The results from the forced-vibration (transient dynamic) analyses considering axial cyclic loading indicated that the nucleus removal increased the dynamic responses at all disc levels. For example, at the denucleated L4-L5 level, after nucleus removal the maximum response values of disc bulge and von-Mises stress in annulus increased by 63.9% and 110.5% respectively, and their vibration amplitudes increased by 97.9% and 139.7% respectively. At other levels, the predicted maximum response values and vibration amplitudes of the stresses and strains also produced 3.1-7.5% and 10.8-30.6% increases respectively due to the nucleus removal, and a relatively larger increase was observed at level L5-S1. It was also found that increasing the preload increased the stresses and strains at all levels but decreased their vibration amplitudes. Nucleus removal at a single level deteriorates the effects of vibration on whole lumbar spine. Also, increasing the preload alters vibration characteristics of the spine. These findings may be useful to provide a guideline for the patients suffering from lumbar disc degeneration to minimize the risk of further injury and discomfort.