To investigate the effects of bacterial endotoxin on lipids and cytokines, and to explain the relationships between their changes, we carried out this study using experimentally Escherichia coli (E. coli) endotoxin-induced septicemic rabbits. The triglyceride and cholesterol concentrations in endotoxin groups were generally high (p$lt;0.01 or 0.05) at all sampling time points (from 3hr to 24 hr), while phospholipid concentrations in endotoxin groups elevated in dose-dependent fashion at 3hr and 6hr after endotoxin injection compared to control group (p$lt;0.05). There were significant negative correlations between lipids changes and cytokines (TNF-α and IL-1β) each other (p$lt;0.05), and endotoxic rabbits having higher triglyceride of cholesterol levels shown relatively better conditions compared with others. As a result, the alterations in the lipid compositions caused by endotoxin may imply an active exhibition of the host defense mechanism rather than the disturbances of lipid metabolism.