Abstract: A method was developed for determining 4 estrogens ( estrone, estradiol, estriol and diethylstilbestrol) in animal products such as egg, chicken, beef and pork by dispersive solid phase extraction ( DSPE) as clean up step and liquid chromatography- tandem quadrupole mass spectrometry ( LC- MS / MS) as detection step. Acetonitrile was added into sample to precipitate the protein and anhydrous Mg SO4 was used for the removal of residual water, and then sample was cleaned up by DSPE using primary secondary amine ( PSA) dipolar adsorbent.Estrogens were detected by LC- MS / MS. The average recovery of 4 estrogens from the samples at three spiked levels could reach 96.63%.The limit of detection ( S / N = 3) ranged from 1.32μg / kg to 16.52μg / kg.