Prenatal glucocorticoids (GCs) exposure leads to affective dysfunction in adulthood, which may be associated with the alterations in hypothalamic-pituitary-adrenal (HPA) axis.Physical exercise has been shown to ameliorate depressive symptoms.The objectives of present study were to investigate whether prenatal exposure to GCs induces depression-like behaviors in adult offspring rats, and determine whether swimming exercise alleviates the depression-like behaviors induced by this paradigm.The results show that dexamethasone (DEX) treatment reduced body weight in 1, 3, 6, 9-week old offspring, induced depression-like behaviors in sucrose consumption test and open field test, and elevated the level of serum corticosterone (CORT) in adult offspring.Four-week swimming exercise reduced serum CORT levels, and alleviated the depressive behavior.These findings suggested prenatal exposure to GCs increase the activity of HPA axis and depression-like behaviors of adult offspring.Swimming exercise decreases HPA activity and ameliorates depression in rats exposed to DEX prenatally.