Lysozyme is commonly found in spots where bacterial infections are most likely to enter the body. Earlier we found that lysozyme possesses five antimicrobial peptide motifs in its N-terminal region which can be generated by newborn pepsin. In this study， we explore the role of these peptides in the anti-inflammatory activity of lysozyme. The five peptides， helix1 (H1)， helix2 (H2)， H1 and H2 connected with a loop (HLH)， H2 extended with either 2 β-strands (H2-S12) or 3 β-strands (H2-S13)， were synthesized and examined for anti-inflammatory action. The five peptides dose-dependently decreased， to different degrees， expression of pro-inflammatory cytokines， TNF-α， IL-6 and IL-1β， in lipopolysaccharide (LPS)- or interferon-gamma (INF-γ)-stimulated mouse macrophage cells (RAW264.7). The HLH peptide and its individual helices (H1 and H2) were markedly the most potent anti-inflammatory. When macrophage cells were stimulated with live bacteria (E. coli)， H1 peptide was the most powerful suppressor of TNF-α and IL-6 expression， providing evidence that the peptide is able to antagonize the pathogen-induced inflammatory response. Receptor binding assay and docking simulation provided evidence that H1 peptide bind specifically to the pocket for endotoxin binding of the toll-like receptor 4 (TLR-4) of macrophage. The results demonstrate， for the first time， the molecular basis of anti-inflammatory action of lysozyme that N-terminal helical peptides are the main contributors. This exciting finding offers new classes of therapeutic peptides with potential in the treatment of infection-induced inflammatory diseases.