Objective: To establish UPLC method for the determination of two components in Caesalpinia decapetala. Method: Separation was performed at 45℃

on a ACQUITY UPLC BEH C18 column (2.1 mm×150 mm

1.7 μm) with a gradient solvent system of acetonitrile-0.1% aqueous formic acid as the mobile phase. The flow rate was 0.3 mL·min-1 and the detection wavelength was 266 nm. Result: The linear response ranges of(1'R

3'S

5'R

8'S

2E

4E)-dihydrophaseic acid-3'-O-β-D-glucopyranoside and (±) Protosappanin B were 0.497-79.6 mg·L-1 (r=0.999 8)

1.50-240 mg·L-1 (r=0.999 9)

respectively. The mean recoveries of the two components were 100.9%(RSD 1.9%)

99.89%(RSD 1.8%). Conclusion: The method is simple and accurate

and is suitable for evaluating the quality of Caesalpinia decapetala.