Near infrared spectra in the range of 11501.4 ～ 6047.7 cm- 1 were used for simultaneously determination four oestrogens and progestogens: estradiol, estriol, medroxyprogesterone acetate and estrone. Constant offset elimination data pretreatment and partial least square regression method were used to resolve the spectra overlap of the four substancesas well as the tetrahydrofuran solvent. 100 samples were taken as the calibration set getting a correlation coefficient of 0. 99. The relative deviations for prediction samples were < 5 %. Some measuring factors influencing regressive accuracy like moistrue, temperature and dissolvent were discussed.