Abstract: OBJECTIVE To establish UHPLC-MS/MS method to determine geniposidic acid in rat plasma and to investigate the effect of salt processing on pharmacokinetics of geniposidic acid in Eucommia ulmoides Oliver. METHODS Chromatographic column: BEH-C₁₈（100 mm×2.1 mm， 1.7 μm); the mobile phase: acetonitrile-0.1% formic acid aqueous solution. The gradient elution program was performed at a flow rate of 0.3 mL/min. RESULTS The main pharmacokinetic parameters of geniposidic acid in raw and salt products were that：AUC_(0-t) were （1 47.18±272.28）， （2 120.694±664.532）ng·h/mL；AUC_(0-∞) were （1 564.42±273.97）， （2 145.61±659.983）ng·h/mL；C_max were （517.59±51.24）， (733.292±261.34)ng/mL；MRT were （2.68±0.11）， （2.551±0.08）h；T_1/2 were （1.37±0.08）， （1.43±0.17） h；T _max were （1.52±0.1）， （1.51±0.1）h. CONCLUSION Salt processing can obviously enhance the absorption of geniposidic acid in Eucommia ulmoides Oliver， and increase the bioavailability.