Endometritis is a major disease in productive bovines, and is also caused by conditional pathogens after delivery. The integrity and activity of bovine endometrial epithelial cells (bEECs) determine the development of endometritis. Tanshinone IIA, a compound purified from Salvia miltiorrhiza bunge, has been reported to have antiinflammatory effects. The aim of this study was to investigate the anti-inflammatory effects of tanshinone IIA in the LPS-induced inflammatory response of bEECs. The results showed that tanshinone IIA inhibited the mRNA expression levels of COX-2 and iNOS, and reduced the expression levels of IL-18, TNF-alpha, IL-6 and IL-8 induced by LPS. In addition, we found that tanshinone IIA inhibited the level of MDA, but increased the activities of CAT and SOD. To evaluate the anti-inflammatory mechanism of tanshinone IIA, we examined the activation of Nrf2. The results showed that the Nrf2 signaling pathway was significantly activated by tanshinone IIA. In conclusion, these results showed that tanshinone IIA exhibited anti-inflammatory and antioxidative effects by activating the Nrf2 signaling pathway.