To explore the differences in body metabolism of experimental animals，the serum samples of four batches of healthy SD rats raised in different periods were compared using proton nuclear magnetic resonance(1H NMR) based metabolomic approach combined with multivariate statistical analysis.The results showed that the contents of several serum metabolites in different groups，including citric acid，pyruvic acid，succinic acid，glutamine，dimethylglycine，changed slightly，while the amounts of alanine，arginine，isoleucine，lactic acid，3-hydroxybutyric acid and choline were fluctuant.Further metabolic pathways analysis showed that amino acid metabolism，ketone body metabolism and choline metabolism were fluctuant in different groups of SD rats.This study provided a new method for the evaluation on the consistency among the different groups of healthy SD rats，and laid a basis for further determination on the biomarkers in serum samples.