Objective To evaluate the value of computed tomography myelography(CTM)in diagnosing the laceration of brachial plexus. Methods Sixteen cases with brachial plexus injury underwent thin-slice high resolution CT scanning two hours after the examination of conventional lumber puncture myelographs.The results of CTM in patients were compared with surgical exploretation and seven patients underwent preoperatively electrophysiological examination .Results There were totally 28 nerve roots injury.Of them,26 were detected by CTM,the accuracy was 92.8%.The main signs of nerve root laceration were the disapperance of the filling defect of ventral and forsal root,the indirect signs were false meningeal cyst,displacement and deformation of spinal cord,twist of nerve root.Conclusion CT myelography is of significant value in diagnosing the laceration of nerve root.