Background: The aim of this study was to investigate whether Quaker Essence of Chicken (with American Ginseng) has an anti-fatigue effect in SD rats. Sixteen Rats were randomly divided into 2 groups, each containing 8 animals. The control group received 2 mL/kg body weight of distilled water. The treated swimming groups were administrated Quaker Essence of Chicken liquid at doses of 1.13 mL/kg body weight for a period of 6 weeks treatment. Another 16 rats were repeated the above experiments but for a period of 8 weeks treatment. At the end of experiments, rats were made to perform swimming exercise and the total swimming time until exhaustion was measured. No mortalities occurred during the study. Physical and behavioral examinations did not reveal any treatment-related adverse effects after dosing. Both six-week (227 ± 153 min) and eight-week (153 ± 64 min) treatment groups showed a significant increase swimming time to exhaustion in comparison to control groups. After swimming, liver glycogen did not increase by the treatment of Quaker Essence of Chicken liquid when compared with control groups. These results suggest that Quaker Essence of Chicken liquid improves swimming endurance and has an anti-fatigue effect.