Essential oils (EOs), derived from medicinal plants, has been reported to possess various bioactivities to treat inflammatory diseases. Therefore, it is urgent to investigate the effect and the mechanism of EOs essential oils as naturally anti-inflammatory agents. The present study indicated thirty-one EOs had different inhibition on lipopolysaccharide (LPS)-induced nitric oxide (NO) production. Moreover, the most potent EOs against NO production in BV2 cells were chuan-xiong, schizonepeta tenuifolia, lemongrass and zedoary turmeric with IC