Abstract： Objective:To confirm the reliability and effectiveness of regenerative peripheral nerve interface (RPNI) as a surface electromyographic signal source in the early stages.Methods:Two patients with upper limb amputation were treated with surgery to construct RPNIs for the anterior interosseous nerve and posterior interosseous nerve of the forearm. Ultrasound examinations were performed at 1, 2, and 3 months postoperatively to observe their muscle structure and blood flow changes. The electromyographic examination was performed to assess changes in electromyographic signals and assess the function of displaced nerves and muscles. And the stability and reliability of its surface electromyographic signal were tested at the third month after surgery.Results:RPNI can observe stable muscle structure and blood flow from the second month after surgery. The electromyography showed a nearly mixed phase electromyographic signal, the nerve conduction velocity and amplitude tended to be normal. At the same time, stable and high signal-to-noise ratio electromyographic signals could also be collected from the body surface.Conclusion:RPNI can provide a reliable and stable surface electromyographic signal source through ischemia, regeneration, and maturation processes, and has broad application prospects in electromyographic prosthetic control.