Abstract: GC-MS/MS was applied to the determination of 12 hypnoticsin in blood. The sample was extracted with a mixture of ethyl acetate,cyclohexane and acetone (2+2+1) by accelerated solvent extraction,and purified using alumina powder online. The extract was then evaporated to dryness by N2-blowing and dissolved in 0.5 mL of methanol. A VF-5MS chromatographic column was used for separation. Electron impact was used for ionization source. MRM was adopted in MS. The linear relationships between the peak area and the mass concentration of 12 hypnotics was kept in the same range of 50.0-1 000 μg·L-1,with the lower limits of determination (10S/N) in the range of 0.02-4.7 μg·L-1. Recovery rates measured by standard addition were in the range of 65.4%-98.2%,with RSD in the range of 0.9%-14.8%.