〔Abstract〕 Objective To investigate the inhibitory effect and mechanism of phillyrin(PHN) on inflammatory response induced by lipopolysaccharide(LPS). Methods An LPS-induced mouse macrophage(RAW264.7) inflammatory model was established to study the secretion of inflammatory cytokines and the expression of related proteins. The effects of PHN at different concentrations on the activity of mouse macrophages were detected by MTT assay. The nitric oxide(NO) release was detected by Griess method. The expression levels of tumor necrosis factor α(TNF-α) and interleukin-6(IL-6) were detected by ELISA assay. The expression level of TLR4 signaling pathway-associated protein was detected by Western blot. Binding affinity was detected by molecular docking. Furthermore, an acute lung injury(ALI) model induced by LPSin vivowas established, and the protective effect of PHN was studied by observing histopathological changes. Results PHN had no significant inhibitory effect on cell proliferation in the concentration range below 30 μmol/L. Furthermore, PHN could inhibit the secretion of NO, TNF-α and IL-6 by LPS-induced macrophage cells. Further studies had shown that PHN inhibited the secretion of cytokines by inhibiting the TLR4 signaling pathway, and molecular docking showed that PHN had a strong affinity with TLR4 protein. In addition, PHN showed good function in vivo anti-inflammatory activity in an LPS-induced ALI model. Conclusion PHN can effectively regulate LPS-induced inflammation, which may be through blocking the TLR4 signaling pathway to reduce the expression of inflammatory cytokines.