The single-dose pharmacokinetics of piroxicam (PIX) in rabbits has been studied.Following oral administration of the drug, the plasma concentration curves showed double peaks with the first at 3.9±1.2h and the second at 5.9±1.0h.Intravenous administration yielded a single peak at 4.7±0.8h.The curves declined smoothly and the peak subsided after bile duct-cannulating.The mean residence time and the area under the plasma concentration curves decreased from 5.5±1.8h and 78.6±25.6μg·h/ml in normal rabbits as opposed to 2.5±0.4h and 40.5±7.92μg·h/ml in bile duct-cannulated rabbits after intravenous administration.These results suggested that the multiple-peak phenomenon of PIX pharmacokinetics was caused by enterohepatic circulation (EHC).The Value of PIX EHC fraction in rabbits was confirmed to be 0.48.