The objective of the paper is to determining the content of paeoniflorin in Rupikang granule by HPLC method. After extracting sample by ultrasound method and diluted ethanol, determining the content of paeoniflorin in Rupikang granule by HPLC method, using C18 chromatog. column, using acetonitrile-0.1, phosphoric acid (15:85) as mobile phase, detection wavelength is 230 nm, flow rate is 1 mL/min-1, column temperature is 40°. The results showed that the paeoniflorin shows good linear relationship in the range of (0.26-4.13) μg, correlation coefficient r = 0.9999, average recovery rate is 99.8%. It was concluded that the treatment method of sample is reasonable, methodol. study meet the requirement of quant. anal., the results is accurate, which can be used in the determination of the content of paeoniflorin in Rupikang granule.