The initiation of calcium oxalate (CaOx) kidney stone formation is highly likely to stem from injury to the renal tubular epithelial cells (RTECs) induced by stimulation from an aberrant urinary environment. CHAC1 plays a critical role in stress response mechanisms by regulating glutathione metabolism. Endoplasmic reticulum (ER) stress and ferroptosis are demonstrated to be involved in stone formation. This study attempted to elucidate the mechanism of ER stress-dependent ferroptosis and the role of CHAC1 in CaOx kidney stones. Here, regulating ER stress and CHAC1 expression are performed in in vivo and in vitro stone models. These findings indicated that 4-Phenylbutyric acid (4-PBA)treatment and CHAC1 deficiency alleviated the ferroptotic status, including restoring GSH content, suppressing Fe