Abstract: Ochratoxin A（OTA） was identified as an important mycotoxin widely contaminating cereals and their derived products， posing a serious threat to human and animal health. Although its hepatorenal toxicity had been clarified by previous studies， its toxic effects on multiple organ systems and the underlying mechanisms were not fully elucidated. To investigate the systemic toxicity of OTA， a subacute mouse exposure model（daily intragastric administration of 1， 2， 3.5 mg/kg BW OTA for 8 days） was established， and the effects of OTA on growth performance， serum oxidative stress levels， and residue distribution in major organs（heart， liver， spleen， lung， kidney） were systematically evaluated. The results showed that：1）OTA exposure significantly inhibited mouse body weight gain in a dose‑dependent manner， and the liver organ index in the high-dose group was significantly reduced（P<0.05）；2）Medium‑dose and high‑dose OTA exposure significantly decreased serum total superoxide dismutase activity， glutathione peroxidase activity， and total antioxidant capacity （P<0.05），indicating that systemic oxidative damage was induced；3）Organ‑specific distribution of OTA residues was observed among the tested organs， with the highest residue level being detected in the kidney（up to 29.4 μg/g），followed by the lung and then the liver， and all three were significantly higher than those in the heart and spleen（P<0.05）. It was confirmed that OTA exposure not only impaired growth performance and induced systemic oxidative stress， but also the high accumulation in the lung suggested that the lung might be a new target of concern in OTA toxicology research. These findings provided important experimental evidence for a comprehensive understanding of the systemic toxicity and mechanisms of OTA.