The chronic intrathecal catheterization of the subarachnoid space in the rat is a very useful model in the research of neuroscience, anesthesiology, neurotoxicity, and etc. To avoid high postoperative mortality and neurological impairment, the catheterization from the lumbar interspace has been widely used in recent years. But one of the most discouraging disadvantages is that the external portion of the chronic indwelling catheters is easily damaged by rats. Besides, the short length of catheter left in the subarachnoid space in addition to its slimness makes it difficult for proper fixation. To improve the abovementioned situations, we designed a protector to protect the external portion of the catheters and developed a simple method for better fixation. Results suggest that this is an excellent method for protecting and fixing the lumbar catheters placed in the subarachnoid space of rats, and this method did not affect the sensory and motor function of the rat. The general conditions of the rats were unswayed.