Objective To study the main factors that influence the serum uric acid in male uricase-deficient rats (Kunming-DY rats) under normal feeding condition. Methods Male Kunming-DY rats, heterozygote rats, and wild-type rats of 45 d old were used in the present study. Their blood without anticoagulation was drawn from their cut tails, and serum samples were obtained by centrifugation. The serum uric acid(SUA), blood urea nitrogen(BUN), and creatinine(Cr) were assayed. Then, the rats were put in metabolic cages to record their intakes and excretion in 24 h. Their urine and feces excreted were collected, and the uric acid was detected. The results between the 3 groups were analyzed, and the relationship between factors in Kunming-DY rats were correlated. Results Compared with the wild-type and heterozygote rats, Kunming-DY rats’ growth was retarded, though they consumed more water. Their SUA, BUN, Cr，and urine increased, and uric acid in the urine and feces also increased. There was a negative relationship between SUA and food consumption. Conclusion The increased SUA in Kunming-DY rats is mainly caused by uric acid synthesized from endogenous purines, and the uricase-deficiency is a disadvantage factor on rats’ growth and renal function.