〔Abstract〕 Objective To investigate the effect and possible mechanism of microRNA-26a(miR-26a) on the synthesis of extracellular matrix(ECM) induced by high glucose(HG)in renal tubular epithelial cells(RTECs). Methods A model of diabetic kidney disease(DKD) was constructed by inducing RTECs with HG. MiR-26a was overexpressed in HG-induced RTECs, and RT-qPCR and Western blot were used to assess the effects of miR-26a on ECM synthesis and ferroptosis-related markers in HG-treated RTECs. Ferrostatin(Fer-1) was used to inhibit ferroptosis in the DKD model, and its impact on ECM synthesis was evaluated. RT-qPCR and Western blot were performed to measure ferroptosis-related markers, and fluorescence microscopy was used to observe the intensity of reactive oxygen species(ROS). Results Compared with the control group, the expression of miR-26a decreased in HG-treated cells, while the expression levels of ECM synthesis-related indexes fibronectin and collagen Ⅰ increased. After overexpressing miR-26a, the HG+miR-26a group showed a significant increase in miR-26a expression and a decrease in fibronectin and collagen Ⅰ expression compared to the HG group. In terms of ferroptosis, the protein and mRNA expression of SLC7A11 and GPX4 significantly decreased, the expression of TFR-1 and ACSL4 significantly increased, and the fluorescence intensity of ROS was significantly enhanced in the HG group compared with the control group. Inhibition of ferroptosis in the HG+Fer-1 group resulted in significant changes in ferroptosis and ECM synthesis-related indicators expression levels compared to the HG group. Furthermore, re-expression of miR-26a in the HG+miR-26a led to significant changes in ferroptosis-related indicators expression levels and decreased ROS fluorescence intensity compared to the HG group. Conclusions In HG-induced RTECs, miR-26a inhibits the occurrence of ferroptosis, thus reducing ECM synthesis.