Abstract: AimTo study the pharmacokinetic process about the concentration in rat plasma of the alkaloids from processed seeds of Strychnos nux-vomica with RP-HPLC method. MethodsHypersil BDS C₁₈ column was used and the mobile phase consisted of acetonitrile-water at the flow rate of 0.8 mL·min^-1. The UV detection wave length was 254 nm. ResultsThe concentration-time data of strychnine, brucine, strychnine N-oxide and brucine N-oxide were all in accordance with an open two-compartment model after iv alkaloids. Their parameters were as follows: T_1/2α were (8±5), (4±3), (6.2±1.7)and (3.0±0.8) min, T_1/2β were (262±125), (416±131), (285±50) and (342±141) min, CL were (17±4), (21±12), (1.9±1.8) and (2.8±1.1) mL·min^-1, V_c were (1.4±0.5), (1.7±1.1), (0.24±0.16) and (0.23±0.06) L·kg^-1, V_d were (6.0±1.2), (12±7), (0.8±0.6) and (1.5±0.6) L·kg^-1, AUC were (57 578±25 578), (35 240±15 616), (93 088±22 375) and (177 712±120 110) h·μg·L^-1, respectively. ConclusionThe method is a good reference for pharmacokinetics in human bodies.