Objective To investigate the block effect of amentoflavone (AF) on the inflammation of mouse BV-2 microglial cells induced by lipopolysaccharide (LPS). Methods BV-2 microglial cells were treated with AF at different concentrations, and cell viability was determined by CCK-8 assay to get the AF concentration that had no effect on the cell viability. BV-2 microglia cells were pretreated with 10 mol/L AF, and 1 hour later, 1.0 g/mL LPS was used to induce inflammatory response in the BV-2 microglial cells. Real-time quantitative PCR was performed to detect the gene expression of interleukin 1β (IL-1β), tumor necrosis factor α (TNF-α), cyclooxygenase 2 (COX2) and inducible nitric oxide synthase (iNOS). The protein expression of COX2 and iNOS were measured by Western blot analysis. Immunofluorescence staining was used to observe the location and expression of COX2 and iNOS. Results CCK-8 showed that 10 mol/L AF did not affect the viability in BV-2 microglial cells. The treatment of 1.0 g/mL LPS could significantly up-regulate the mRNA expression of IL-1β, TNF-α, COX2, iNOS, and the protein expression of COX2 and iNOS. Compared with the only LPS treatment, 10 mol/L AF pretreatment markedly decreased the elevated gene and protein expression induced by LPS. In addition, AF significantly inhibited the expression of COX2 and iNOS, and less microglial cells were activated. Conclusion AF can inhibit the inflammation of BV-2 microglial cells induced by LPS.