To determine the content of amino acid to clarify the curative effect and the functioning mechanism of DanHong injection on microscopic.Methods：OPA reversed phase high performance liquid chromatography (HPLC)，precolumn derivatization method fluorescence detection， gradient elution were used.Mobile phase A was 15mol/L Na2HP04 - Na2B07 buffer (pH = 7.95)， B was acetonitrile - methanol - water (45：45：15， V/V/V).As for linear gradient elution， mobile phase B in 6 min increased from 5% to 17.2%， increased from 17.2% to 52% in 6-35 min.Results：1) Fifteen kinds of amino acids were isolated within 35 min; 2) using principal component analysis， three groups were well separated; 3) using the SPSS analysis of variance， there were six amino acids in the separation between groups was statistically significant.Conclusion：Danhong injection can improve metabolic trend of amino acid in cerebral infarction rats serum through adjusting perturbed pathways