Objective:To develop and validate a three dimension finite element model of the earlier-period degeneration L4-5 lumbar motion segments reconstruced from CT Images. Method:To develop such FE model,a 138 frames of CT images with the distance 0.75 mm were gathered in clinic,from which the plane coordinate data were obtained,and then these 2D data were transformed into 3D coordinate. Finally,the 3D FE model of a Chinese woman the earlier-period degeneration L4-5 lumbar motion segment was developed using Patran analysis software,and then the model was validate by a 400N stress force. Results:The result shows that the model has good effect visually and mathematically,which was consisted of 27 130 nodes,113 834 elements,including Solid elements 113 153,Area elements 161,Link elements 520. The results of load test of the aforementioned FE model was consistented the published results. Conclusion:Based on CT image and with the help of CAD methods,this three dimension finite element model of the earlier-period degeneration L4-5 lumbar motion segments can be constructed automatically with excellent simulation results.