Objective: The LC-MS method was used to determine the content of major coptis alkaloids in rabbits plasma simultaneously and to investigate pharmacokinetics of berberine

palmatin and jatrorrhizine. Method: Blood samples were collected at different time after oral administration of different ratio of Coptdis Rhizoma and Euodiae Fructus. The plasma concentration of berberine

palmatin and jatrorrhizine was determined by LC-MS. Result: The pharmacokinetics parameters were calculated by two-compartment model

AUC0-t

t1/2α

t1/2β

Cmax of berberine were: 3 762

4 456

4 823 μg·L-1·min-1;51.33

38.93

39.02 min;6.69×106

0.45×106

4.77×106 min;6.47

6.65

7.64 μg·L-1;Tmax was all at 90 min.The pharmacokinetics parameters AUC0-t

t1/2α

t1/2β

Cmax of palmatin were:2 291

2 635

3 069 μg·L-1·min-1;43.16

46.95

50.57 min;3 440

3 598

2 788 min;3.41

4.83

5.32 μg·L-1;Tmax was all at 90 min.The pharmacokinetics parameters AUC0-t

t1/2α

t1/2β

Cmax of jatrorrhizine were: 521

429

806 μg·L-1·min-1;59.53

254.06

43.42 min;9 700

259

1 348 min;0.78

1.16

1.51 μg·L-1; Tmax was all at 90 min. Conclusion: The relationship between ratio of Coptis and AUC showed a good linearity.