Abstract: An LC-MS/MS method was used for the evaluation of a novel antihypertension candidate pharmacokinetics of ATPT in Beagle dogs.After ig administration of 7.5,15 and 30 mg/kg ATPT,the determined t_max and t^1/2 of ATPT in dogs were 0.7-1.0 h and 3.5-4.3 h，respectively.While the areas under the curve (AUC_0-∞) were (5 465.9±1 748.7),(7 846.2±3 547.4) and (15 490.9±8 292.4) ng ·h/mL at three doses，respectively.Good linearity was observed between c_max/AUC_0-∞ and dose (R²>0.98 ) after a single ig administration of 7.5,15 and 30 mg/kg in dogs.After adjustment of dose,the absolute bioavailabilities of ATPT in dogs were 39.7%，28.5% and 28.1%,respectively.It presented a linear pharmacokinetics for ATPT in Beagle dogs within the dose range of the study.