Fourier transform infrared spectroscopy(FTIR) was applied to the study of human myelocytic leukemia(HL-60) xenografted in nude mice.Experiment results show that(1) the peak of CH_3 and C-O of molecule of protein shifts to a certain extent in cancerous tissues,(2) the relative intensity of 1746cm~(-1) is very strong in normal tissues,but it is very weak in malignant tissues,(3) the relative intensity of the stretch vibration of PO_2~-in phosphodiester group is obviously strong,(4) the ratio of the relative intensity of deformed vibration of the adipose molecule and the deoxyribose vibration of CH_3 was higher in normal tissues,but it is almost equal in malignant tissues.The result might indicate that the FTIR could be used in the clinical diagnoses of the malignant tissues of human myelocytic leukemia(HL-60) xenografted in nude mice,and it also suggests that the nude mice tumor models could be a new method for the FTIR spectroscopic studies of tumor.