Objective To investigate the feasibility of amplitude of intraoperative nerve action potentials (NAP) for early quantitative diagnosis of peripheral nerve injury. Methods The sciatic nerve injury model were established in 16 rabbits. Intraoperative NAP were recorded after 4 weeks. According to amplitude of NAP, the injuried nerve were divided into 3 groups: NAP ＜ 100 μV in A group, 100 μV ≤NAP ＜ 500 μV in B group, NAP ≥ 500 μV in C group. Nerve specimen 1cm distal to injuried point were resected that received glycine silver stain and image analysis including number, diameter and cross section area of regenerative axons. Footprint parameter and ulcer area were measured and contrasted between each two groups. Results The number, diameter and cross section area of A group regenerative axons have significant difference with B and C group, no significant difference between B and C group; Footprint parameter and ulcer area have significant difference in each two groups. Conclusion Amplitude of intraoperative NAP can be a quantitative criteria to diagnose the degree of peripheral nerve injury that provides experiment evidence for guide intraoperative decision-making in clinical practice.