beta-patchoulene (beta-PAE) is one of the essential tricyclic sesquiterpenes of patchouli oil while beta-patchoulene epoxide (beta-PAO) is the oxidative product of beta-PAE which can only be found in the oil with long storage period. Our previous researches demonstrated that both beta-PAE and beta-PAO exert potent anti-inflammatory activity in vivo, but which one is more valuable still remains uncertain. Therefore, this study adopts the model of LPS-stimulated RAW264.7 macrophages to compare beta-PAO with beta-PAE on the anti-inflammatory activity. According to our results, beta-PAO was superior to beta-PAE on anti-inflammation as evidence by lowering the protein and mRNA expressions of several pro-inflammatory cytokines including tumor necrosis factor-alpha (TNF-alpha), interleukin-12 (IL-12), interleukin-1 beta (IL-1 beta), and monocyte chemotactic protein-1 (MCP-1). beta-PAO was also better than beta-PAE in reducing the productions of nitric oxide (NO) and prostaglandin E-2 (PGE(2)) through inhibiting inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 signaling pathway. The results above provided experimental basis for the conclusion that beta-PAO was more potent than beta-PAE in anti-inflammatory activity in vitro.