Abstract: Atractylenolide Ⅲ (ATL-Ⅲ), a sesquiterpene compound isolated from Rhizoma Atractylodis Macrocephalae, has revealed a number of pharmacological properties including anti-inflammatory, anti-cancer activity, and neuroprotective effect. This study aimed to evaluate the cytoprotective efficiency and potential mechanisms of ATL-Ⅲ on corticosterone injured rat phaeochromocytoma (PC12) cells. Our results demonstrate that ATL-Ⅲ increases cell viability and reduces the release of lactate dehydrogenase (LDH). The results suggest that ATL-Ⅲ protects PC12 cells from corticosterone-induced injury by inhibiting the intracellular Ca²⁺ overloading, inhibiting the mitochondrial apoptotic pathway and modulating the MAPK/NF-κB inflammatory pathways. These findings provide a novel insight into the molecular mechanism by which ATL-Ⅲ protected the PC12 cells against corticosterone-induced injury for the first time. Our results provide the evidence that ATL-Ⅲ may serve as a therapeutic agent in the treatment of depression.