Objective To investigate the differential expression of miR-124-3p in peripheral blood and clinical sig-nificance of patients with β-thalassemia.Methods Peripheral blood samples were collected from 33 patients with β-thalassemia and 30 healthy controls in Ningde Municipal Hospital Affiliated to Ningde Normal University from June 2021 to August 2022.The expression level of miR-124-3p was detected.Luciferase reporter gene was used to verify the interaction between miR-124-3p and ERF 3'UTR.The correlation between differential expression of miR-124-3p and β-thalassemia was analyzed and the clinical diagnostic value of miR-124-3p for β-thalassemia was eval-uated.Results Compared with healthy control individuals,the expression of miR-124-3p was significantly up-reg-ulated in patients with β-thalassemia(P＜0.001).The genotype of miR-124-3p high expression group was 84.2%β0(16/19),the genotype of low expression group was 55.6%β+(10/18).ROC curve analysis showed that miR-124-3p had predictive efficacy for β-thalassemia(AUC:0.842).Luciferase reporter gene analysis showed that ERF gene was the regulatory target of miR-124-3p.Conclusions The differential expression of miR-124-3p in patients with β-thalassemia is closely related to the genotype and clinical severity of thalassemia,and ERF is negatively reg-ulated by miR-124-3p.miR-124-3p may be an effective diagnostic biomarker for β-thalassemia.