The main problem in peripheral nerve repair is adhesion, axonal escape, and the ingrowth of extraneurial tissue into the wound. Meticulous microsurgical neurorrhaphy is one of possible answer for these problem. Shielding of nerve suture is another attractive practice. But the results are still unpredictable. We compared the results of nerve repair between microsurgical epineurial neurorrhaphy plus silastic cuff shielding group and epineurial neurorrhaphy group in the sciatic nerve of white rat. The reasults we obtained are as follows; 1. Silastic cuff shielding method was effective for reducing abnormal neurial growth and neuroma formation into the surrounding soft tissue. 2. Some adhesion was formed over the silastic cuff, but there was no adhesion at the inner space of the cuff. 3. Silastic cuff could prevent fibrous tissue ingrowth into the nerve. 4. The slit of the silastic cuff provided vascular ingrowth between surrounding connective tissue and nerve tissue. 5. No evidence of foreign body reaction was observed in and out of the silastic cuff. 6. Nerve conduction test showed a little supperior results in the silastic cuff shielding group. Silastic cuff shielding method in nerve suture might be recommanded to prevent axonal escape, fibrous scar tissue ingrowth to the nerve, and fibrous adhesion in clinical practice. But, it seemed that the final evaluation of the functional recovery of the nerve needed long term follow-up and nerve conduction study.