Objective:To screen for peptides that specifically bind to PreS1 antigen from a phage-displayed peptide library.Methods: The PreS1 antigen was used as the target molecule to screen the binding peptide from the Ph.D.-7 peptide library with phage display technique,and the positive clones were identified by ELISA.Results: After three rounds of biopanning,the binding peptides were screened from the peptide library by ELISA and competitive inhibiting ELISA.Sequencing result showed that the binding peptides had high affinity and specificity.Conclusion: A peptide binding PreS1 antigen has been successfully obtained by screening the phage display library,which paves a way for the diagnosis and treatment of hepatitis B infection.