This experimental study investigated the effectiveness of three methods of neurorrhaphy, nerve grafting and nerve implantation in phrenic nerve transfer for treatment of brachial plexus root avulsion injuries. 180 Sprague-Dawley rats were used. The electrophysiological, histological and muscle functional evaluations were performed at 1, 2, 3, 4, 5 and 6-month postoperatively. Variable recovery in each group was found at different postoperative intervals. At six months after operation, the following results were observed in descending order of superiority: neurorrhaphy, nerve grafting, nerve implantation. Nerve implantation demonstrated a recovery of function of 75.76% and the characteristic electrical activity of the phrenic nerve might contribute to the motor endplate regeneration. Our experimental results will serve as the basis for our clinical practice.