Objective：To investigate whether epidural injection of compound solution can cause intraspinal adhesion and inflammatory reaction of nerve roots by observing the pathological condition of epidural cavity and nerve root after the injection. Methods：Totally 24 healthy adult white Japanese rabbits were randomly divided into four groups equally（n=6）：control group（group A），steroid + narcotic injection group（group B），steroid + narcotic+ vitamin B injection group（group C），steroid + narcotic+ vitamin B+ traditional Chinese medicine injection group（group D）. In group B，C，D，each rabbit was given epidural injection of compound solution once a week for four weeks. The dura mater，nerve roots，and spinal cord specimens were performed for pathologic detection at the 1st，4th and 8th week respectively after discontinuation. Results：Neither fibroplasia nor cicatrization was observed by visual inspection. The results of HE staining indicated the presence of hemaleucin effusion and phlogistic infiltration in the epidural cavity，thickening of the dura mater and inflammatory exudation around the nerve roots in partial specimens. No abnormality was seen in specific staining. Immunohisto－chemistry showed that type Ⅱ collagen fiber proliferation occurred in the subdural and epidural cavity at the 4th week in group B，C and D and dura maters were slightly thicker in group B，C and D than in group A at the 8th week. Under the electron microscope，desmocyte in group B，macrophage in group C，focal thickening of the myelin sheath and endoneurial collagen fibril in group D were observed at the 4th week. Increasing number of desmocytes in group B，C，D at the 8th week were found. Conclusions：Mild inflam－mation and slight type Ⅱ collagen fibers proliferation can be detected around the spinal cord and nerve roots after epidural injection of compound solution once a week for consecutive four weeks. No organ damage in spinal cord and nerve root can be found if these changes exist within eight weeks. Epidural injection of compound solution is feasible if the puncture is accurate.