The objective of this paper is to study and establish the reversed phased high performance liquid chromatog. method for determination of paeoniflorin in WuLing Granules; Phenomenex (4.6 mm × 250 mm, 5 μm) column was used as stationary phase; the mobile phase was composed of methanol and water (25:75); the flow rate was 1.0 mL/min-1; the UV absorbance detection wavelength was set at 230 nm; the external standard method was used.The calibration curve was linear within the range of 0.0225-0.3375 μg (r = 0.9999); the average recovery of Paeoniflorin was 102.50%, with RSD 1.42% (n = 9); this method was convenient, rapid, sensitive, reproducible and accurate.It can be used in determination of Paeoniflorin in WuLing Granules.