Objective　To provide an operation zone for spine surgery.   Methods　Observed the course and the adjacent relation of thoracolumbar spine segmental vascular and surveyed the related datas by the adult corpse specimens and normal adult CT images.   Results   We could observe the course and the adjacent relation of segmental vascular，one segmental artery has two main branches. That between the upper and lower segmental vessels consists a relatively non-vascular nerve "safety range" where the intervertebral space locates. And we had surveyed the related datas. The distance between adjacent segmental arteries in the T10/11, T11/12, T12/L1, L1/2, L2/3 is (23.38±0.88), (25.57±0.95), (29.07±1.11),(32.63±1.28),(33.62±1.47)mm respectively. And the observation of the three-dimensional CT image in the T10/11,T11/12,T12/L1,L1/2,L2/3 is （23.43±1.40）、（25.63±2.01）、（29.13±2.10）、（32.59±2.10）、（33.52±2.11）mm mm respectively.  Conclusions    The operating space is safe enough for some surgeries like thoracoscope - assisted anterior approach intervertebral fusion and we can take the intervertebral disc as a reference mark. we can also take the three-dimensional CT image as a reference for surgical plan by surveying the safety range