Aim To establishan inflammatory model of mouse monocyte macrophages ( RAW264. 7) using li-popolysaccharide (LPS), and to investigate the antiinflammatory activity and mechanism of tanshinone II-A (Tan IIA). Methods Cell viability was determined by CCK-8 method. Cell migration was detected by Tr-answell apparatus. TNF-α, IL-6, IL-1 p, MCP-1 content in cell supernatant was analyzed using ELISA method. The protein expression of MMP-2, MMP-9, TLR4, κB-α, p-κB-α, NFκB and p-NFκB in RAW264.7 cells was investigated by Western blot. Results Tan IIA significantly inhibited .the secretion of TNF-α, IL-6, IL-1β and MCP-1 in LPS induced RAW264.7 cell culture medium , and significantly down-regulated the expression of matrix metalloprotein-ase-2 (MMP-2), MMP-9, TLR4, p-κB-α and p-NFκB , inhibited IκB-α phosphorylation and NFκB entry into the nucleus and activation. Conclusion Tan IIA can inhibit the release of inflammatory factors through the regulation of TLR4/IκB-α/NFκB signaling pathway.