Anti-oxidative Activity of the Extracts from Houttuynia cordata Thunb. Fermented by Lactic Acid Bacteria Anti-oxidative activity;fermentation;Houttuynia cordata Thunb;Lactobacillus sakei;Leuconostoc mesenteroides; This study was performed to evaluate the possibility of application of lactic acid bacteria fermentation to increase the anti-oxidative activity of extracts from Houttuynia cordata Thunb. Houttuynia cordata Thunb. was fermented by two species of lactic acid bacteria, Leuconostoc mesenteroides 4395 and Lactobacillus sakei 383. The anti-oxidative activities of Houttuynia cordata Thunb. extracts were analyzed both before and after fermentation. Anti-oxidative activity was determined by in vitro assays to measure 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging and super oxide dismutase (SOD)-like activities, and by determining total flavonoid and total phenolic compound contents. The extracts of fermented Houttuynia cordata Thunb. had higher anti-oxidative activity than the unfermented control. The DPPH scavenging activity of the extracts after fermentation by Leuconostoc mesenteroides 4395 at 30℃ for 5 days was 71.67±0.52%, and after Lactobacillus sakei 383 fermentation at 35℃ for 5 days was 70.11±0.67%; these activities were both about 20% higher than the control. Increases of about 10 mg GAE/g of total phenolic compounds were found in both fermented extracts and both contained about 6 mg quercetin equivalents/g of total flavonoids, compared with 35.90±0.61 mg/g and 21.69±1.52 mg/g in the control, respectively. These results also suggested that fermentation time and temperature were important factors in determining the anti-oxidative effect of extracts from fermented Houttuynia cordata Thunb. These findings should be valuable for the development of medicines or functional foods with antioxidative activity.