Background and Objective: Strenuous and excessive exercise or training may cause muscle and internal organ injuries, of which liver injury is a typical pathological feature of sports tissue injury. Liver injury can affect the performance of sports and jeopardize the health of athletes or sports enthusiasts. Studies have shown that exercise-related injuries are associated with oxidative stress and inflammation. Therefore, the pathway of enhancing the antioxidant and anti-inflammatory capacity of the body can be attempted to ameliorate exercise-related liver injury during excessive exercise. Studies showed that dandelion polysaccharide (DP), a natural product present in dandelion, has obvious anti-inflammatory and antioxidant activities. The study aimed to investigate the protective effects of DP on liver injury induced by excessive exercise. Materials and Methods: Overexercise model was performed with Kunming mice, during the training, the DP 100 and DP 200 groups received 100 and 200 mg/kg of DP daily, while the control groups (Normal and Model groups) received equal volume of saline. After 4 weeks of excessive exercise, mice were executed and tested for liver injury. Results: Compared with Model group, ALT and AST levels were significantly reduced in the DP groups and cell morphology was more regular and aligned in liver tissues; the antioxidant ability of liver was significantly increased and the level of the lipid oxidation product MDA was significantly decreased in liver; and pro-inflammatory factors, such as TNF-a, significantly decreased and the levels of anti-inflammatory factors increased significantly in serum and liver; Nrf2 and HO-1 proteins in Keapl/Nrf2/HO-1 signaling pathway increased significantly and phosphorylation ratio of protein JAK2 and STAT3 in JAK2/STAT3 pathway and the protein expression of HMGB1, TLR4 and p-NF-KB p65 in HMGB1/TLR4/NF-KB signaling pathways decreased significantly. Conclusion: The DP intervention can ameliorate excessive exercise-induced liver injury and this protective mechanism is involved in activating Keap1/Nrf2/HO-1- 1 antioxidant pathway and inhibiting JAK2/STAT3 and HMGB1/TLR4/NF-KB pro-inflammatory signaling pathway.