Objective To observe and explore the effect and clinical value of percutaneous electrical stimulation on nerve regeneration after end-to-side neurorrhaphy in rats. Methods Thirty-two SPF male S-D rats were randomly divided into four groups (n=8):group A, the normal control group; group B, with end to end neurorrhaphy of musculocutaneous nerve injury matched to the ulnar nerve; group C, with end to side neurorrhaphy of musculocutaneous nerve injury matched to the ulnar group; and group D, with end to side neurorrhaphy of musculocutaneous nerve injury matched to the ulnar nerve plus postoperative transcutaneous electrical stimulation (30 min per day for 6 weeks). Electromyography, postoperational nerve conduction velocity, the histological and ultrastructural changes of the nerve fibers were examined, and NF-200 expression in frozen sections was observed using imunohistological staining, to assess the recovery of muscle strength of the diseased side limb and the neuroregeneration in the rats after treatment. Results The amplitude and conduction velocity of the groups C and D were lower than that of the group A, the latency was higher than that of the group A, while the amplitude and conduction velocity of the group D were lower than that of the group C, and the latency was higher than that of the group C. The wet weight ratio of the biceps brachii muscle and the cross-sectional area of muscle fibers in the groups B, C and D were lower than those in the group A, and the recovery of muscle in the group C was the worst. The expression of NF-200 in the rats of groups B, C and D was significantly lower than that in the group A, and the expression of NF-200 in the group D was significantly higher than that in the group C, but still significantly less than that in the group B (P< 0.05). Electron microscopy showed mature myelinated fibers in the group B, whereas unmyelinated fibers were the main component and the myelin sheath was poorly developed in the group C. The myelin regeneration in the group D was better than that in the group C, but still some unmyelinated nerve fibers were seen. Conclusions The percutaneous electrical stimulation can effectively promote nerve axonal regeneration and can delay the atrophy of the target muscle after end-to-side neurorrhaphy. Though there is difference compared with the end-to-end neurorrhaphy, the end-to-side neurorrhaphy is still an effective method in clinical repair of peripheral nerve injury.