Objective：To establish a canine model of lumbosacral nerve root compression, so as to search for treatment for radicular pain and numbness caused by nerve root compression. Methods: Eighteen male adult mongrel dogs were evenly randomized into 3 groups: 7 days group, 14 days group and 28 days group. A 5 mm long thick silica tube (diameter 34 mm) were implanted under right L6, L7 and S1 nerve root to establish the compression model; the left side served as self controls. Results: Dynamic observation with histopathology and immunohistochemical staining showed that, after the nerve root nerve root compression, the myelinated nerve fibers decreased and there was ultrastructure changes of the nerve fibers, such as Schwann cell cytoplasm swelling and edema, Wallerian degeneration, and demyelinated degeneration of axons. Conclusion: The ultrastructural changes of nerve root are the pathological basis of the function loss of the nerve root. The present model is more closer to the model of lumbar intervertebral disc herniation and stenosis of nerve root compression and it provides a basis for treatment of compressioncaused radicular pain and numbness in clinic.