Abstract: Objective: To investigate the effects of marine fish oligopeptide composite preparation (MFOCP) on reducing uric acid and repairing kidney damage and the underlying mechanisms. Methods: A high uric acid mouse model was established using hypoxanthine and potassium oxonate. After successful modeling, different doses of MFOCP were used to intervene for 4 weeks. The activity of xanthine oxidase (XOD), levels of uric acid (UA), creatinine (Cr), and blood urea nitrogen (BUN) in the serum of high uric acid mice, levels of inflammatory factors in serum and kidney tissue, activities of XOD and adenosine deaminase in liver tissue, pathological detection of kidney tissue, and mRNA expressions of uric acid transport and reabsorption proteins in the kidney were measured to evaluate the uric acid reducing effect of MFOCP and its role in repairing kidney damage. Results: The low, medium, and high doses of MFOCP significantly reduced serum UA content (P<0.01), XOD activity (P<0.05), and inflammatory cytokine interleukin-6 content in kidney tissue (P<0.05) and ameliorated renal tissue lesions in the model mice. The medium and high doses of MFOCP also significantly reduced serum Cr and BUN contents (P<0.01), and significantly increased the relative expression levels of organic anion transporter 2 (OAT2) mRNA and adenosine triphosphate binding cassette transporter G2 (ABCG2) mRNA in kidney tissue (P<0.05). Conclusion: MFOCP effectively reduced serum uric acid levels in high uric acid model mice and repaired the kidney damage caused by high uric acid, which mechanism of action might be by reducing the activity of XOD in the serum to decrease uric acid synthesis or regulating the mRNA expression levels of uric acid transporters OAT2 and ABCG2 to promote uric acid excretion.