【Objective】 To unmask the mechanisms underlying the suppression of infant neuropathic pain after peripheral nerve injury.【Methods】Rats were subjected to spared nerve injury（SNI）at postnatal 10 d or 33 d. Mechanical paw withdrawal thresholds as well as spinal interleukin-10（IL-10）and the β-endorphin precursor gene proopiomelanocortin（POMC）mRNA expression were detected 7 d after surgery. The IL-10 or β-endorphin neutralizing antibody was intrathecally injected for 3 d（the 7th-9th day after surgery）and mechanical paw withdrawal thresholds were tested 1 h after each injection. Spinal IL-10 mRNA and POMC mRNA were detected by RT-qPCR. 【Results】In contrast to adult rats，infant rats subjected to SNI displayed no mechanical allodynia but an increase in spinal cord IL- 10 and POMC mRNA expression. Intrathecal administration of the IL- 10 antibody and β-endorphin antibody evoked neuropathic pain- like behaviors in infant rats. SNI-induced POMC mRNA increase was blocked by the pretreatment with intrathecal the IL-10 antibody，while the increased IL- 10 mRNA expression was not affected by the β- endorphin antibody pretreatment.【Conclusions】The suppression of neuropathic pain in infant rats may be mediated by activation of spinal IL-10/β-endorphin pathway.