After oral administration of low, middle, high dose of simulative Maijunan tablets to SD rats and puerarin, hydrochlorothiazide at middle dosage to SD rats separately, plasma samples were collected at different times and treated with acetonitrile to precipitate protein.  The contents of puerarin and hydrochlorothiazide in plasma were determined by HPLC method.  The mean plasma concentration-time profiles of puerarin and   hydrochlorothiazide at different dosages of medication administration were processed by 3P97 pharmacokinetic software and SPSS statistics 17.0 software.  The results indicated that the in vivo kinetic processes of puerarin in rats were all fitted to a two-compartment open model and hydrochlorothiazide fitted to a one-compartment  open model.  Hydrochlorothiazide in vivo kinetic process in rats was in accordance with the linear dynamics.  The combination of hydrochlorothiazide and rhynchophylla with pueraria promoted the absorption, reduced   the elimination rate and prolonged the action time of puerarin in vivo.  Meanwhile, the combination also   promoted the absorption rate and the bioavailability, prolonged the action time and the accumulation time of  hydrochlorothiazide in vivo.