It is suggested that ovariectomy induces body weight gain primarily in the form of adipose tissue in rodents. Since liver peroxisome proliferator-activated receptor ${alpha}$ (PPAR${alpha}$) and uncoupling 2 (UCP2) are involved in the regulation of energy expenditure, it was investigated whether swim training regulates ovariectomy-induced adiposity and steatosis through liver PPAR${alpha}$ and UCP2 activation in female ovariectomized mice, an animal model of postmenopausal women. Swim-trained mice had significantly decreased adipose tissue weights compared with sedentary control mice. Histological analysis showed that hepatic lipid accumulation was inhibited by swim training. Concomitantly, swim training significantly increased mRNA levels of PPAR${alpha}$ and its target genes responsible for peroxisomal fatty acid ${eta}$-oxidation, such as acyl-CoA oxidase, enoyl-CoA hydratase/3-hydroxyacyl-CoA dehydrogenase and thiolase in the liver. Moreover, swim training induced the mRNA expression of UCP2. These results suggest that swim training can effectively prevent adiposity and steatosis caused by ovariectomy, in part through activation of liver PPAR${alpha}$ and UCP2 in female obese mice.