To provide an easily synthesizable new lipopolysaccharide adsorbent (bacterial endotoxin adsorbent), enabling easy adjustment of various relating structures, and usable for the adsorption of various lipopolysaccharides and provide a screening method for the adsorbent.

The method for the screening of a bacterial endotoxin adsorbent comprises the binding assay (binding experiment) of a peptide library and a radioactive labeled lipid A produced by introducing a radioactive element to a phosphonoxyethyl derivative of a biosynthesis precursor-type lipid A or an E.coli-type lipid A. The invention further relates to a bacterial endotoxin adsorbent composed of a specific peptide library found by the screening method.