Objective: To investigatewhether Yulangsan Polysaccharide (YLSP) affects the anti-Duck Hepatitis B Virus (anti-DHBV) in brown duck. Method: Sixty one-day-old ducks were selected. After 13 days

positive ducks infected 0.2 mL serums of DHBV DNA were detected by PCR

and were randomly divided into five groups:YLSP high-

middle-

low-dose groups(5

2.5

1.25 g·kg-1)

aciclovir(ACV) group(0.1 mg·kg-1) and model group with 10 brown ducksin every group. The serums were respectively collected before administration

7 and 14 days after administration and 3 day after withdrawal. The DHBV DNA was detected by fluorescence quantitative(FQ)-PCR assay. The extent of liver injury was observed by HE staining. Result: Compared with model group

the serum content of DHBV DNA in ACV group and YLSP 5

2.5

1.25 g·kg-1 groups was significantly decreased. The content of DHBV DNA in ACV group

middle-does group and low-dose groups showed a rebound phenomenon after withdrawal. The results indicatedthat YLSP had significant protective effects against the injury of ducks' liver. Conclusion: YLSP not only has an inhibited effect to DHBV

but also has a protective effect on injury of liver.