To　investigate　the　biodegradation　of　sex　steroid　hormones,　a　high　efficient　degrading　strain　ZY3　was　isolated　from　the　active　sludge　of　sewage　treatment　station　in　a　prophylactic　plant,　which　can　degrade　3-methoxy-17βhydroxy-1,　3,　5(10),　8(9)-Δ4-estren　(named　MHE),　a　kind　of　streroid　hormones.　Based　on　its　morphology,　physiological　and　biochemical　characters,　as　well　as　16S　rDNA　sequence　analysis,　this　strain　is　identified　as　Raoultella　sp.　Experiment　results　show　that　the　appropriate　range　of　temperature　and　pH　for　strain　ZY3　using　MHE　is　25-37°C　and　9.0-11.0,　respectively.　The　growth　of　strain　will　be　restrained　when　the　substrates　concentration　is　more　than　20　mg/L.　81%　of　degradation　rate　of　MHE　can　be　obtained　by　strain　ZY3　for　72　h.　The　existence　of　metal　ions　such　as　Na+,　Mg2+　and　Ca2+　can　facilitate　the　growth　of　strain　ZY3,　and　the　heavy　metal　ions　including　Sn2+,　Mn2+　and　Cd2+　can　restrain　its　growth.　The　strain　can　utilize　the　estrogenic　compounds　easily　as　its　sole　carbon　source,　but　can　not　utilize　the　other　PAHs　such　as　phenol,　anthracene　and　naphthalene.