Objective It has been reported that Psammosilene tunicoides has agood pharmacological effect of anti-inflammatory and analgesic, but the anti-inflammatory effect and mechanism of Psammosilene tunicoides is not clear. Therefore, the aim of this study was to investigate the anti-inflammatory effect and mechanism of the Psammosilene tunicoides and its triterpenoid compounds through RAW264.7 cell inflammatory model inducedby LPS. Methods Using RAW264.7 cell inflammation modelinduced by LPS, the level of NO and PGE2 in cell supernatant was detected by ELISE Reagent and the expression of COX-2, iNOS, IL-6, TNF-α mRNA in cells was detected by PCR and the expression of NF-κB signaling pathway related proteins (IKKβ, photo-lκBα, NF-κBP65, photo-NF-κBp65) in total protein, cytoplasm and nucleus of cells were detected by westerning blotting. Thusthe anti-inflammatory mechanism of triterpenoids compounds of Psammosilene tunicoides was investigated. Results Triterpenoid compounds from Psammosilene tunicoides(QA, GYP) can significantly reduce the level of NO and PGE2 in the supernatant of RAW264.7 cells after activation, while TSPT have no significant effect on the level of NO and PGE2 in the supernatant of the cells. The results showed that the expression of COX-2 and iNOS mRNA in RAW264.7 cells was significantly decreased by the triterpenoids compounds from Psammosilene tunicoides. The results were consistent with the quantitative results of PGE2, which was consistent with the quantitative results of PGE2 and NO. Different components had different effects on the release level of inflammatory mediators and the expression of synthase mRNA. The expression of NF-κBp65 within the cells decreased. The expression of NF-κBp65 in the nucleus increased, the expression of p-NF-κBp65 in the total protein increased, and the expression of p-NF-κBp65 in the total protein was increased. After the intervention of the triterpenoids compounds, the activation of IKKβ and the degradation of p-IκBα protein were inhibited, and the expression of p-NF-κBp65 in the total protein was also decreased, thus inhibiting the transfer of NF- κBp65 to the nucleus in the cytoplasm. Conclusion We have studied the anti-inflammatory effect and mechanism of Psammosilene tunicoides and its triterpenoids compounds vitro. They have good anti-inflammatory and analgesic effects, and can inhibit the release of inflammatory mediators and the gene expression of enzymes. The anti-inflammatory mechanism are related to the inhibition of activation of NF-κB signaling pathway.