Abstract: Lutein ester is mainly composed of dipalmitate and dimyristate, which is the most abundant in Tagetes erecta L.. In order to study the distribution of lutein esters in Tagetes erecta L., the Fourier transform infrared spectrometer was used to obtain the spectrum of its petal, stalk and leaf. In the Fourier transform infrared spectra of the petal, stalk and leaf, the characteristic absorption peak of the carbonyl was observed at near 1735 cm^-1, which indicated that the petal, stalk and leaf contained a certain amount of esters. Because of the absorption peak of carbonyl was overlapped by the absorption band of protein, its strength could not be determined accurately. For the purpose of obtaining information on the absorption peak of carbonyl, curve fitting analysis technique was used to separate the overlapped peaks of the absorption band. The results of curve fitting analysis showed that the order of lutein ester content in Tagetes erecta L. from high to low was the petal, stalk and leaf. The results showed that Fourier transform infrared spectrum could be used to analysis the content of esters in Tagetes erecta L. quickly and qualitatively, which provides a convenient method for studying the synthesis and transportation of esters in Tagetes erecta L..

Key words: Fourier transform infrared spectrum, Tagetes erecta L., Lutein ester, curve fitting analysis