A liquid chromatography coupled with mass spectrometry (LC/MS) based metabonomics approach was applied to characterize the aging of rats, and the anti-aging effect of total flavones of Epimedium (TFE), a traditional Chinese medicine, has also been investigated. Serum samples collected from 4, 10, 18 and 24 month-old rats and TFE-administered rats have been profiled by LC/MS. Thirty age-related endogenous metabolites were discovered by partial least squares (PLS) and Hotelling's T(2) control chart, among which 25 metabolites were structurally identified by MS(n) analysis and ten of them were further confirmed via authentic chemicals. All important age-related metabolites, such as unsaturated fatty acids, saturated fatty acids, nucleotides, carnosine, ergothioneine and amino acids, displayed age-related changes, and most of them were reset to a younger level after TFE administration. This study indicated that aging could be characterized by changes of lipid metabolisms and accumulation of free radicals. The anti-aging effects of TFE might due to the intervention on lipid metabolism and its property of anti-oxidation.