The purposes of this study were to investigate the modulation of spleen dendritic cells (DCs) and natural killer T (NKT) cells， and to assess the effect of α-galactosylceramide (α-GalCer) injection on DC-NKT axis during overtraining or excessive exercise. Two-month-old female Sprague-Dawley rats (n 36) were trained with a progressively increasing load for 9 weeks. At 36 h and at 7 d post-training， the rats were euthanized according to experimental design Whole blood was used to detect hemoglobin(Hb)， plasma was analyzed for hormones testosterone (T) and corticosterone (C)，and the spleen was harvested for detecting DCs and NKT cells. Results indicated the 36 h after training， a decrease in Hb， T and C concentrations reflected overtraining or excessive exercise. DC count and function was depressed at sampling timepoints， wherea the NKT cell populations were only decreased at 7 d after training. α-galactosylceramide treatment had no effect on DC counts but activated DC function. NKT cell numbers were enhanced by 69%. These data suggested that DC and NKT cell levels were regulated differently depending on the physiological circumstance， and DC and NKT depression might play an important role in post-training immunosupression. Moreover， immunotherapy by extending the knowledge of DCs and NKT cells may be a useful tool in the treatment of exercise-related immune depression