Aim Paeoniflorin6′ Obenzene sulfonate (CP25) was synthesized to improve oral absorption.This study was performed to investigate absorptive behavior and mechanism of CP25 in intestine.Methods The effects of drug concentration, intestinal segments, gender as well as ATP binding cassette (ABC) transporter inhibitors on absorption of CP25 were studied in a situ singlepass intestinal perfusion rat model.Meanwhile, Paeoniflorin (Pae)was tested and served as control group.The concentration of tested drugs was measured by HPLC.Results The results showed intestinal absorption of CP25 was neither segmental dependent changes nor gender difference.Transepithelial transportation would not change with increasing concentrations of CP25, which suggest a passive transport was the main pattern of CP25.Additionally, absorption of CP25 was much better than that of Pae in small intestine.When compared with Pae, CP25 gave a 1.82fold permeability rate.Finally, the results indicated Pae was substrate of Pglycoprotein (Pgp), but was not the substrate of breast cancer resistance protein and multidrug resistance associated protein 2.Among the used ABC inhibitors, the absorption rate of Pae could only be increased by? Pgp inhibitor Verapamil and GF120918, while CP25 had no remarkable alteration.Conclusion CP25 has better absorptive features than that of Pae, which may be attributed to its lipophicity enhancement and be unaffected by Pgp efflux.