摘要Background Contralateral C7 (cC7) transfer had been widely used in many organizations in the world,but the outcomes were significantly different.So the purpose of the study was to evaluate the outcome of patients treated with cC7 transferring to median nerve and to determine the factors affecting the outcome of this procedure.Methods A retrospective review of 51 patients with total root avulsion brachial plexus injuries who underwent cC7 transfer was conducted.All of the surgeries were performed with two surgery stages and median nerve was the recipient nerve.The cC7 nerve was used in three different ways.The entire C7 root was used in 11 patients; the posterior division together with the lateral part of the anterior division was used in 15 patients; the anterior or the posterior division alone was used in 25 patients.The mean follow-up period was 6.9 years.Results The efficiency of the surgery in these 51 patients was 49.02％ in motor and 62.75％ in sensory function.The patients with entire C7 root transfer obtained significantly better recovery in both motor and sensory function than the patients with partial C7 transfer.The best function recovery could be induced if the interval between the two surgery stages was 4-8 months.Conclusions cC7 transfer is an effective procedure in repairing median nerve.But using the entire C7 root transfer can obtain better recovery; so we emphasize using the entire root as the donor.The optimal interval between two surgery stages is 4-8 months.