Objective:To validate the stability,tissue specificity,and sensitivity of circulating miR-124 for detecting lead neurotoxicity,so as to provide a basis for the evaluation of lead neurotoxicity using circulating miR-124. Methods:A rat middle cerebral artery occlusion model was established using Zea-Longa line plug method. Blood samples were collected,centrifuged,and aliquoted,then immediately tested or stored at different times under conditions of room temperature,2 ℃ to 8 ℃,and -70 ℃ to -90 ℃ the expression of miR-124 was detected by RT-qPCR method. Hepatotoxicity,cardiotoxicity and nephrotoxicity models were established with acetaminophen(1 250 mg/kg),isoprenaline(2.5 mg/kg)and gentamycin(80 mg/kg),respectively. The expression of circulating miR -124 was detected and compared in the collected pre -modeling and post -modeling blood samples. Rat neurotoxicity models were established with lead acetate(300 and 600 mg/kg). ELISA method was used to detect the changes of IL-10,IL-1β,and TNF -α. The sensitivity was evaluated by comparing the time of changes detected of cytokines and circulating miR-124. Results: Compared with fresh blood samples,circulating miR-124 remained stable when the blood samples were stored at room temperature for 6 h,at 2 ℃ to 8 ℃ for 24 h,at -70 ℃ to -90 ℃ for 36 d,and for three freeze-thaw cycles. The stability could support the requirement so flaboratory. Circulating miR-124 has good tissue specificity since no significant changes were noted in rat hepatotoxicity, cardiotoxicity and nephrotoxicity models. Compared with the cytokines,circulating miR-124 could evaluate neuroinflammation caused by lead exposure with a more sensitive manner. Conclusion:Circulating miR-124 has good stability,tissue specificity and sensitivity, and can be used as a potential biomarker of evaluating lead neurotoxicity.