In an attempt to isolate and characterize peptides mimicking epitopes of metalloprotease and explore theirimmunological protection against Schistosoma japonicum(S.japonicum),polyclonal anti-metalloprotease sera wasprepared to screen a 12-mer random peptide library to isolate phages binding specially to antisera IgC.Then,phage ELISA,animal immunization,DNA sequencing,Western blotting and enzymatic activity neutralizinganalysis were used to characterize the selected phage clones.All of ten randomly picked clones were shown to bepositive.Five peptides of different amino acid sequences deduced from DNA sequences were obtained and two ofthem (peptides 2 and 3) could induce significant reduction (31.0% and 31.8%,respectively) in worm burden andhigh reduction (52.6% and 54.9%,respectively) in liver eggs per gram (LEPG),while,unexpectedly,others(peptides 1,4 and 5) could not elicit enough protection against infection of S.japonicum.Peptides 2 and 3 could berecognized by S.japonicum infected mouse sera (IMS) and could elicit neutralizing Abs.The results show thatpeptides 2 and 3 are antigenic and immunogenic.They are true mimics of epitopes of metalloprotease and useful asnovel vaccine candidates against S.japonicum.Cellular & Molecular Immunology.2005;2(3):219-223. In an attempt to isolate and characterize peptides mimicking epitopes of metalloprotease and explore theirimmunological protection against Schistosoma japonicum (S.japonicum), polyclonal anti-metalloprotease sera wasprepared to screen a 12-mer random peptide library to isolate phages binding specially to antisera IgC.Then , phage ELISA, animal immunization, DNA sequencing, Western blotting and enzymatic activity neutralizinganalysis were used to characterize the selected phage clones. All of ten randomly picked clones were shown to bepositive. Fles peptides of different amino acid sequences deduced from DNA sequences were obtained and In liver eggs per gram (LEPG), while, unexpectedly, others (both of them) (peptides 2 and 3) could induce significant reduction (31.0% and 31.8% peptides 1,4 and 5) could not be elicit enough protection against infection of S. japonicum. Peptides 2 and 3 could be recognized by S. japonicum infected mo use sera (IMS) and could elicit neutralizing Abs. These results show that peptides 2 and 3 are antigenic and immunogenic. they are true mimics of epitopes of metalloprotease and useful as vaccine delivery against S. japonicum. Cellular & Molecular Immunology. 2005; 2 ( 3): 219-223.