Objective To observe pharmacological effect of Paidu Yangyan(PDYY) capsules on lowering serum uric acid(SUA) in uricase-deficient rats. Methods Seven male uricase-deficient rats weighting 180-220 g were orally administrated with the suspension of PDYY capsule at the dose of 0.42 g/kg for 5 d. Before and 2 h after the fifth administration, collected the blood, urine and feces. The SUA, uric acid in urine and feces were determined by uric acid kits with the phosphotungstic acid method, then the total uric acid in urine and feces were calculated. Results Compared with those before administration, SUA was significantly lowered(P<0.05), and the total uric acid in feces in 5 d significantly increased(P<0.05). While, the total uric acid in urine in 5 d decreased without significance(P=0.109). Conclusion Orally administration of PDYY capsule was able to lower SUA, and the mechanism may be associated with increasing uric acid excretion via feces.