Abstract: The blood sample (1.00 mL) was taken, and then 2 mL of acetonitrile and 50 mg of sodium chloride were added. After oscillation for 10 min, the above mixture was centrifugated for 10 min at the speed of 8 000 r·min^-1 at -4℃. PSA (15 mg) and C₁₈ (25 mg) were added in the supernatant. After oscillation for 5 min, the above centrifugal operation was repeated. The supernatant was filtered on 0.22 μm organic microporous membrane. UHPLC-MS/MS was applied to the determination of 4 aconitum alkaloids, i.e. hypaconitine,mesaconine,aconitine and yunaconitine in the filtrate. Agilent ZORBAX Eclipse Plus C₁₈ chromatographic column was used as stationary phase, and the mixture of 0.1% (mass fraction) ammonia and methanol mixed in different ratios was used as mobile phase in gradient elution. ESI⁺ and multi-reactions monitor mode were adopted in MS/MS. Linear relationships between values of peak area and mass concentration of the 4 aconitum alkaloids were kept in definite ranges. Detection limits(3S/N) of the method ranged from 0.010 to 0.035 μg·L^-1. On the base of blank sample, test for recovery was made by standard addition method; values of recovery found were in the range of 96.3%-109%, with intra-day RSD (n=6) and inter-day RSD (n=6) of recovery amounts in the ranges of 2.3%-4.2% and 0.70%-6.7%.