Objective: The aim of the paper was to study the relationship between 18 kinds of amino acid contents and cold or hot nature of traditional Chinese material medica and establish discriminant function. Method: Extracting eighteen kinds of amino acid from thirty kinds of TCM. Seventeen kinds of amino acid contents were determined by high performance liquid chromatography(HPLC) with precolumn phenylisothiocyanate derivatization spectrophotometry. Tryptophan were determined by ultraviolet spectrophotometry. The Fisher discriminant analysis was used to analyze the relationship between amino acid and cold or hot nature of traditional Chinese material medica. Result: Form the determinantion of 18 kinds of amino acid contents

it showed that the average amino acid contents of the heat is 1.32 times than the one of the cold

the correct rate is ninety percent analyzed by Fisher discriminant analysis. Conclusion: Form the results of fisher discriminant of 18 variables

it revealed that there are many differences between the cold and hot property in 18 kinds of amino acid contents. Based on the analysis of the determined data

a discrimination function was established and it could distinguish cold and hot property of Chinese herbs.