Abstract: Objective: To investigate the changes of serum amino acid levels in type 1 and type 2 diabetic rats,and its correlation between the amino acid metabolism and diabetes.Methods: The type 1 diabetes mellitus model induced by streptozotocin and type 2 spontaneous goto-kakizaki diabetic male rats were divided into the experiment group,and male Wistar rats injected by the same volume of sodium citrate suspension were set as the control group.The serum levels of 14 kinds of amino acid level were determined by liquid chromatography-mass spectrometry.Results: Compared with the control group,the levels of valine and isoleucine in experiment group increased(P<0.05 to P<0.01),and the levels of glutamine,lysine,arginine and tyrosine in experiment group decreased(P<0.05 to P<0.01).Conclusions: The levels of branched-chain amino acid and basic amino acid in type 2 diabetic mode increase and decrease,respectively.The change of amino acid level can provide some clues and help in the occurrence of complications.