Objective: To discuss and compare the plasma pharmacokinetics after three oral Panax notoginseng saponin (PNS) administrations in beagle dogs. PNS is the main active ingredient of the traditional Chinese medicine (TCM) Panax notoginseng. Although its outstanding therapeutic efficacy has been demonstrated by various researchers, its broader application is restricted by the low bioavailability of PNS.Methods: An ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the simultaneous quantification of notoginsenoside R1, ginsenoside Rg1, ginsenoside Rb1, ginsenoside Rd, and ginsenoside Re in beagle dog plasma was developed and validated. The plasma samples were subjected to liquid-liquid extraction with acetone and methanol, and separated on an ACQUITY C18 column (100 × 2.1 mm ID, 1.7μm) using acetonitrile and water as the mobile phase with a run time of 4.5 min. Results: The analytes were detected without interference in Selected Reaction Monitoring mode with positive electrospray ionization. The validated method was successfully used in comparative pharma-cokinetic studies of the five saponins in beagle dogs after oral administration of three PNS preparations. Blood samples were collected up to 192 h after administration and pharmacokinetic parameters were calculated using DAS 3.20 and SPSS 17.0. The AUC0-t values of Re and R1 were significantly higher in soft capsules than in hard capsules. However, the AUC0-t values between hard and soft capsules were not significantly different for the other three components—Rb1, Rd and Rg1. Conclusion: Our intuitive analysis suggests that the bioavailability of PNS in soft capsules is greater than in hard capsules.