The spinal segment C4-C6 of the cervical region is one of the most frequent site for injuries in spinal cord. Cervical degenerative disc disease develops due to loss of hydration in the intervertebral discs with increasing age. The spinal segment progresses to develop painful conditions due to high flexion and rotation movements in the upper extremity bones. The main aim of the study to analyse the effects of intervertebral disc degeneration on biomechanics of the cervical spine. The three dimensional computed tomography image was used and the finite element models of the cervical spine were developed with various levels of intervertebral disc degeneration at the C4-C6 functional spinal unit. The developed model is validated with the published data. The biomechanical effects of mild and moderate disc degeneration on the mechanical behaviour of cervical spine were studied using the developed Finite element models. The annulus fibrosis and nucleus pulposus material properties were varied to achieve moderate degeneration. The validated model is modified to various conditions with different mechanical properties and the effects intradisc pressure and progressive degeneration on the range of motion and on intradisc pressure. The analysis and the comparison is made between mild, moderate with normal human cervical spine in terms of progressive intervertebral disc degeneration. Based on this study the range of motion decreased with degeneration and the intra disc pressure increased with progressive degeneration.