The objective of this study was to investigate the biological activities of fermented mugworts and their effects on the lipid metabolism in hyperlipidemia-induced rats. The proximate compositions of two kinds of mugwort, Artemisia capillaris Thumberg and Artemisiae asiaticae Nakai, were compared before and after fermentation. In both types of mugwort crude protein and amino nitrogen contents markedly increased with fermentation. Thrombolytic activity determined from the size of the clear zone on a fibrin plate was higher for the Artemisiae asiaticae Nakai, especially in the fermented sample. Antioxidative activity according to DPPH(1,1-diphenyl-2-picrylhydrazyl) radical scavenging effects was higher for Artemisia capillaris Thumberg but no significant differences were found between the samples after fermentation. The body weights of hyperlipidemia-induced rats that were fed the mugworts for 4 weeks were lower than those of the control group. In all the mugwort-fed rats serum total cholesterol and LDL-cholesterol levels remarkably decreased. Furthermore the fermented mugworts were found to be more effective at decreasing triglyceride (TG) levels. It is also noteworthy that the highest HDL-cholesterol levels were observed in the rats treated with the fermented Artemisiae asiaticae Nakai. And fatty liver weights were higher in the rats fed Artemisia capillaris Thumberg. In conclusion the feeding of fermented Artemisiae asiaticae Nakai was effective for increasing thrombolytic activity and HDL-cholesterol levels as well as reducing TG levels in rats.