Objective: To establish an HPLC method for the determination of nucifefine in rat plasma and to investigate the pharmacokinetics of nucifefine in rats after oral administration of alkaloidal extract of Nelumbo nucifera.Method: The analysis was performed on an Agilent Zorbax-SB C18 column（4.6 mm × 150 mm

5 μm） at 25 ℃ with the mobile phase of acetonitrile-water-triethylamine-glacial acetic acid（27∶ 70.6∶ 1.6∶ 0.78） at a flow rate of 1.0 mL·min-1.The detecting wavelength was set at 270 nm.The plasma samples were collected after oral administration of the alkaloidal extract of Nelumbo nucifera in Wistar rat.The concentrations of nuciferine in plasma were measured by using HPLC method and the pharmacokinetic parameters were calculated by WinNonlin 5.0.1.Result: The calibration curve of nuciferine was linear in the range of 20 ～ 1 000 μg.L-1 with the correlation coefficient of 0.998 3.The intra-day and inter-day precision of this method were 2.24%-3.20%

5.54%-6.95% respectively

and accuracy was 4.25%-7.00%.The extraction recoveries were 87.2%-103.7%.The main pharmacokinetic parameters of nuciferine after adiministration of the alkaloidal etract of N.nuifera to rats were:t1/2（4.18 ± 2.50）

（4.32 ± 1.01）

（6.05 ± 3.72） h

tmax（1.50 ± 0.41）

（2.25 ± 1.19）

（1.88 ± 0.25） h

Cmax（278.75 ± 38.98）

（621.75 ± 137.81）

（1 146.50 ± 249.44） μg.L-1

AUC0→t（1 796.10 ± 680.87）

（4 463.49 ± 1 892.42）

（7 452.08 ± 3 594.24） h.μg-1.L-1.The form of nuciferine in Wistar rat can be described as first-order kinetic model.Conclusion: The method is proved to be sensitive

selective and simple and have been successfully applied to the pharmacokinetic study of nucifefine.