This study was conducted to determine the antioxidative activity of Hericium erinaceus (HE) and we investigated that HE extract contributes to cell proliferation and to anti-LPS-induced inflammation. HE extract showed high DPPH free radical scavenging activity. However, the reducing power activity slightly increased in compare with control. Nitrite scavenging activity, ABTS radical scavenging activity, SOD-like activity of HE were elevated in dose-dependent. The level of total phenolic and flavonoid showed 30.06 mg/100 g and 33.86 mg/100 g, respectively. Linoleic acid oxidation inhibition had reached a maximum level on the fourth day and started to drop from the fifth day. HE extract contributes to cell proliferation on the RAW 264.7 cell. Our finding demonstrated that water extracts of HE possess significant antioxidant activities and may be suggested a new potential source of anti-inflammatory medicines.