Abstract:A method was established for the separation and determination of diethylstilbestrol and four sedatives （estazolam， alprazolam， chlordiazepoxide and diazepam） in pig blood tofu by modified solid-phase dispersive extraction with high performance liquid chromatography. The anhydrous sodium sulfate and florisil（the ratio of quality 4 ∶ 1）was the dispersing agent and clean-up reagent in the process of modified solid-phase dispersive extraction. The methanol was chose as the solvent .The estrogen and sedatives were separated on C18 column （5 μm， 250 mm × 4.6 mm i.d.）employing methanol∶acetonitrile∶water=30∶30∶40 as mobile phase and deter－ mined using UV detector at 235 nm. The column temperature was 30 ℃.The flow rate of mobile phase was 1.0 mL/min. The linearity was good in the range of 0.010 μg/mL-10 μg/mL with the correlation coefficients above than 0. 999 2. The limit of detection of sedatives was 10 ng/g and the limit of detection of diethylstilbestrol was 15 ng/g The average recoveries of estrogen were 82.4 % to 104.5 %. The relative standard deviations were1.7 %-3.5 %. The method is simple， quick and inexpensive， which was available for the detection of diethyl－ stilbestrol and sedatives in pig blood tofu.