Abstract: OBJECTIVE To study the pharmacokinetic characteristics and differences of ellagic acid in rats after oral administration of Euphorbia hylonoma Hand-Mazz. extract and ellagic acid monomer. METHODS SD rats were intragastrically administered with 3 g·kg^-1 of Euphorbia hylonoma Hand-Mazz. extract and 205.5 mg·kg^-1 of ellagic acid monomer(containing an equal amount of ellagic acid). Plasma was collected at different time points and determined by HPLC. The pharmacokinetics of ellagic acid was applied to the blood concentration of ellagic acid by DAS 2.0 software. The pharmacokinetic parameters were calculated. RESULTS After the rats were given the Euphorbia hylonoma Hand-Mazz. extract, the following pharmacokinetic parameters were obtained:t_max=0.25 h; C_max=(1.32±0.30)mg·L^-1; AUC_(0-t)=(2.55±0.54)mg·h·L^-1; AUC_(0-∞)=(3.30±0.53)mg·h·L^-1; t_1/2β=(69.32±2.37)h. However, the rats were given the ellagic acid monomer, the following pharmacokinetic parameters were obtained: t_max=0.50 h; C_max=(0.40±0.09)mg·L^-1; AUC_(0-t)=(1.30±0.25)mg·h·L^-1; AUC_(0-∞)=(1.81±0.23)mg·h·L^-1; t_1/2β=(8.16±1.18)h. The former was half the peak time of the latter, and the peak concentration and area under the curve is increased by about 3.30 and 1.46 times, respectively, and the half-life was extended by about 8.49 times. CONCLUSION There are significant differences in pharmacokinetic behavior between ellagic acid compounds in the two different administrations of extracts and monomers. After the rats were given the Euphorbia hylonoma Hand-Mazz. extract, compared with the oral ellagic acid monomer, the bioavailability of ellagic acid compounds is significantly improved.