The calibration curves were constructed with a series of diluted concentrations in blank plasma by plotting the peak area ratio of the analytes to IS against the concentration of each analyte. The results are illustrated in Table 2. The results demonstrated that calibration curves showed good linearity in the linear range of the analytes with the correlation coefficient r more than 0.99. The LLOQ samples of six rat plasma samples independent of the calibration curves were determined. The results are listed in Table 3. It was observed that the LLOQs of seven alkaloids were less than 2 ng mL−1 and that of four phenolic acids were less than 20 ng mL−1.Their RSDs of inter-day and intra-day were less than 15% and the accuracies ranged from 80% to 118%, respectively. These results demonstrated that the limits were sufficient enough for the pharmacokinetic study of 11 analytes after oral administration of JJT tablet.