Through axial application of a vertical compressive load of 8 kg on 3-dimensional photoelastic models of the spine, the change in the status of stresses according to 3 different postural angulation of an intervertebral disc with or without nucleus pulposus was observed. 6 specimens of 3-dimensional photoelastic models of the spine were made of epoxy in 3 different angulation such as flexion, normal and extension. The nucleus pulposus portion was replaced with silicon in 3 models, and the 3 were made without silicon. Stresses on the intervertebral disc were analyzed according to threee different postural angulations of the intervertebral disc with the nucleus pulposus and without the nucleus pulposus. The results of these study are as follow:1. In an erect neutral posture with the nucleus pulposus, the stress concentration was much increased at the posterior portion rather than at the anterior portion. Also, the high stress was concentrated at the medial and central portion. In an erect neutral posture without the nucleus pulposus, the stress concentration was much increased at the anterior portion rather than at the posterior portion, and the stress distribution seemed to be locally concentrated. 2. In a maximal flexed posture, the stress concentration was much increased at the anterior portion rather than at the posterior portion. Comparing the presence of the nucleus pulposus with the absence of the nucleus pulposus, the stress concentration was lower at the anterior portion in the presence of the nucleus pulposus than in the absence of the nucleus pulposus. Howerver, the stress distribution at the posteror portion was nearly same in the two groups. According to the analysis of the stress distribution diagram, as a whole, the stress pattern around the disc was evenly distributed. 3. In a maximal extended posture, the higher concentration of the stress distribution at the anterior and medical portion rather than in the posterior and lateral portion was observed. The stress concentration was higher in the presence of the nucleus than in the absence of the nucleus pulposus. 4. Comparing the maximal flexed posture with a maximal extended posture, in the presence of the nucleus, at the anterior portion, the stress concentration in the flexed posture was much decreased compared with the extended posture. In the absence of the nucleus pulposus, at the anterior and posterior portion, the stress concentration in the extended posture was much decreased compared with the flexed posture.