This study examined the effects of Corni Fructus administration on the exercise performance and fatigue accumulation in the forced swimming test (FST). The ICR mice were divided randomly into four groups: water-treated FST (control), 500 mg/kg of red ginseng-treated FST (RG), 500 mg/kg of water extract of Corni Fructus-treated FST (CFW), and 500 mg/kg of 30% EtOH extract of Corni Fructus-treated FST (CFE). After FST, an autopsy was performed, and the soleus muscle and serum were collected. The experimental result show that the running time increased in the CFW. In addition, the soleus muscle showed that glycogen was increased by CFW and CFE. Furthermore, CFW significantly regulated GOT (glutamic oxaloacetic transaminase), GPT (glutamic pyruvic transaminase), BUN (blood urea nitrogen), ammonia, LDH (lactate dehydrogenase), D-lactate, TG (triglyceride), and FFA (free fatty acid) in serum. On the other hand, CFE regulated the above factors but not significantly. Overall, CFW and CFE in FST are considered effective in preventing fatigue by controlling the liver enzyme, kidney enzyme, and fatigue-related factors, and the CFW is considered to be more effective than CFE.